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Re: [CTPP] Test your knowledge of population, using Census Game "Bracketology"

by Nancy Reger

Thanks Elaine- People here are all over this! Nancy Nancy Reger | nreger(a)morpc.org Deputy Director, Transportation | Mid-Ohio Regional Planning Commission T: 614.233.4154 | | F: 614.233.4254 111 Liberty Street, Suite 100 | Columbus, OH 43215 [cid:image001.png(a)01CE2A27.EEB73BC0]<http://www.morpc.org/> [cid:image002.png(a)01CE2A27.EEB73BC0] <http://www.facebook.com/morpc> [cid:image003.jpg(a)01CE2A27.EEB73BC0] <http://www.twitter.com/morpc> From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of Elaine.Murakami(a)dot.gov Sent: Tuesday, March 26, 2013 1:02 PM To: ctpp-news(a)chrispy.net Subject: [CTPP] Test your knowledge of population, using Census Game "Bracketology" One of my FHWA friends passed this Census game along, in case you haven't found it yet. Population Bracketology (appropriate for March Madness) based on population data-Metro or State. It is a fun and an interesting way to learn more about relative metro or State populations. Your correct responses are in green and mistakes show up in bright red. http://www.census.gov/dataviz/visualizations/057/?intcmp=sldr1 I am a supporter of using gamification in transportation planning applications. I would like to see more experimentation on using these kinds of techniques for studying mode choice and trip/activity planning. Elaine Murakami FHWA Office of Planning 206-220-4460 (in Seattle)

12 years, 4 months

[CTPP] Test your knowledge of population, using Census Game "Bracketology"

by Elaine.Murakami＠dot.gov

One of my FHWA friends passed this Census game along, in case you haven't found it yet. Population Bracketology (appropriate for March Madness) based on population data-Metro or State. It is a fun and an interesting way to learn more about relative metro or State populations. Your correct responses are in green and mistakes show up in bright red. http://www.census.gov/dataviz/visualizations/057/?intcmp=sldr1 I am a supporter of using gamification in transportation planning applications. I would like to see more experimentation on using these kinds of techniques for studying mode choice and trip/activity planning. Elaine Murakami FHWA Office of Planning 206-220-4460 (in Seattle)

12 years, 4 months

[CTPP] New! Index Supplements for 2010 Census and American Community Survey Datasets

by Brooks

We are pleased to announce the release of a new consolidated master index for the U.S. Census 2010 Summary File 1 (SF1) and American Community Survey (ACS) 5 Year datasets. The files and documentation are the result of a voluntary effort of Dr. Michael Greenwald (personal) and Jonathan Brooks (Texas A&M Transportation Institute) and are available free of charge via the web address below: http://tti.tamu.edu/group/transit-mobility/sf1acsindex/ What is the challenge the index files address? The U.S. Census Bureau publishes wonderfully rich data products based on the Decennial Census and American Community Survey. They also provide high-quality geographic datasets through the TIGER geography program. SF1, ACS, and TigerLine datasets all have identification fields; such as FIPS code, LOGRECNO number, or name field. Unfortunately, no common identification field is available that is capable of linking the three datasets out-of-the-box. For example: In Lane County, Oregon the record index value for Census Block Group 1 in Census Tract 1 is 119370 for 2010 SF1 datasets, but for ACS datasets the same Block Group is number 4514 (ACS 2006-2010) or 4513 (ACS 2007-2011). The master index files solve this data interoperability challenge. How do the index files overcome the data-linking challenge? The master index files act as an intermediate between TIGER, SF1 and ACS datasets. Each consolidated index file contains record identifier numbers from 2010 Census SF1, the 2006-2010 ACS, the 2007-2011 ACS, and FIPS location codes for Census Tracts, Census Block Groups, and even Census Block geographies. The index files are stored in comma-delimited format and as such are compatible with many types of software (e.g. Microsoft Excel, Microsoft Access, SAS, SPSS, ArcGIS, etc.). You can use the same consolidated master index to connect the records from the SF1, the ACS 2006-2010 or the ACS 2007-2010 to their correct Census Tract, Census Block Group or Census Block! Simply connect your Census datasets to the master index file and then join up to another dataset. Please note that the index files do not contain any population or demographic data of any kind; they are simply for linking between disparate datasets. The normal Census Bureau warnings about comparing SF1 Decennial Census data and ACS sample data still apply. There is a consolidated index file for each state, Washington DC, and Puerto Rico. The files are available as a whole or by state via the website. Who would find these files useful? Professionals working with TIGER geographies and population/demographic data from the Census Bureau may find the master index files to be a useful tool for linking datasets; such as: * Transportation or Land Use Planners; * GIS Technicians; * Public Health Officials; * Economists; and * Demographers. Who produced the files? Where can I download/learn more? The index files and accompanying documentation are the result of a voluntary effort of Dr. Michael Greenwald (personal) and Jonathan Brooks (Texas A&M Transportation Institute). Texas A&M Transportation Institute is voluntarily providing a home to the files and is in no way responsible for the accuracy of or use of the files. http://tti.tamu.edu/group/transit-mobility/sf1acsindex/ What if I still have questions? Please contact Dr. Michael J. Greenwald via e-mail (michael.j.greenwald(a)gmail.com<mailto:michael.j.greenwald(a)gmail.com>). Dr. Greenwald will respond as time constraints allow. Jonathan P. Brooks. Associate Transportation Researcher Transit Mobility Program Texas A&M Transportation Institute 701 N Post Oak Rd, Suite 430 Houston, TX 77063 Tel 713.613.9206 | Cell 806.440.2462 http://tti.tamu.edu/group/transit-mobility [cid:image001.jpg(a)01CE2716.2800ADE0]

12 years, 5 months

[CTPP] Bills in congress proposing to make ACS voluntary.

by Weinberger

Hi all, It is worth noting that efforts to make the ACS voluntary are again proposed in the House and Senate. Each bill seeks to make participation voluntary except for name, contact information, date and number of people living in household, each proposes to eliminate the fines, and oddly, each proposes that no one be compelled to reveal religion, but that is already in Title 13. The current status of each bill is as follows: The Senate bill was introduced and referred to the Committee on Homeland Security and Governmental Affairs, the House bill was Referred to the House Committee on Oversight and Government Reform. Currently H.R 1078 and the identically worded S. 530 (text below) call for: H. R. 1078 To make participation in the American Community Survey voluntary, except with respect to certain basic questions, and for other purposes. IN THE HOUSE OF REPRESENTATIVES March 12, 2013 Mr. POE of Texas (for himself, Mr. LAMBORN, Mr. DUNCAN of South Carolina, Mr. JONES, Mr. HUELSKAMP, Mr. CHAFFETZ, Mr. SAM JOHNSON of Texas, Mr. SCALISE, Mr. WALBERG, Mr. AUSTIN SCOTT of Georgia, Mr. GOWDY, Mr. FORTENBERRY, Mr. CULBERSON, Mr. HALL, Mrs. ELLMERS, Mr. LATTA, and Mr. LUETKEMEYER) introduced the following bill; which was referred to the Committee on Oversight and Government Reform ________________________________ A BILL To make participation in the American Community Survey voluntary, except with respect to certain basic questions, and for other purposes. Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, SECTION 1. PARTICIPATION IN AMERICAN COMMUNITY SURVEY. (a) Optional Questions- Section 193 of title 13, United States Code, is amended by adding at the end the following: `The Secretary shall include, in the instructions for completing any survey authorized under this section, a statement indicating that answering any question other than questions that solicit the information described in section 221(c)(2)(A) is optional.'. (b) Refusal To Participate- Section 221 of title 13, United States Code, is amended-- (1) in subsection (a), by striking `Whoever, being over eighteen years of age,' and inserting `Except as provided in subsection (c), any person older than 18 years of age who'; and (2) by amending subsection (c) to read as follows: `(c)(1) Notwithstanding any other provision under this title-- `(A) no person may be compelled to disclose information relative to the person's religious beliefs or to membership in a religious body; and `(B) except as provided in paragraph (2), no person may be fined or otherwise compelled to answer questions in connection with the survey, conducted by the Secretary of Commerce, which is commonly referred to as the `American Community Survey'. `(2) Paragraph (1)(B)-- `(A) shall not apply to any question that elicits-- `(i) the name of the respondent; `(ii) contact information for the respondent; `(iii) the date of the response; or `(iv) the number of people living or staying at the same address; and `(B) does not waive any penalty imposed for conduct described in subsection (b).'. 113th CONGRESS 1st Session S. 530 To make participation in the American Community Survey voluntary, except with respect to certain basic questions, and for other purposes. IN THE SENATE OF THE UNITED STATES March 12, 2013 Mr. PAUL (for himself, Mr. MCCONNELL, Mr. VITTER, and Mr. JOHANNS) introduced the following bill; which was read twice and referred to the Committee on Homeland Security and Governmental Affairs ________________________________ A BILL To make participation in the American Community Survey voluntary, except with respect to certain basic questions, and for other purposes. Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled, SECTION 1. PARTICIPATION IN AMERICAN COMMUNITY SURVEY. (a) Optional Questions- Section 193 of title 13, United States Code, is amended by adding at the end the following: `The Secretary shall include, in the instructions for completing any survey authorized under this section, a statement indicating that answering any question other than questions that solicit the information described in section 221(c)(2)(A) is optional.'. (b) Refusal To Participate- Section 221 of title 13, United States Code, is amended-- (1) in subsection (a), by striking `Whoever, being over eighteen years of age,' and inserting `Except as provided in subsection (c), any person older than 18 years of age who'; and (2) by amending subsection (c) to read as follows: `(c)(1) Notwithstanding any other provision under this title-- `(A) no person may be compelled to disclose information relative to the person's religious beliefs or to membership in a religious body; and `(B) except as provided in paragraph (2), no person may be fined or otherwise compelled to answer questions in connection with the survey, conducted by the Secretary of Commerce, which is commonly referred to as the `American Community Survey'. `(2) Paragraph (1)(B)-- `(A) shall not apply to any question that elicits-- `(i) the name of the respondent; `(ii) contact information for the respondent; `(iii) the date of the response; or `(iv) the number of people living or staying at the same address; and `(B) does not waive any penalty imposed for conduct described in subsection (b).'. Penelope Z. Weinberger CTPP Program Manager AASHTO 202-624-3556 ctpp.transportation.org

12 years, 5 months

Re: [CTPP] Working with County flow data

by Patricia Becker

When you talk about the number of variables, do you mean combinations or sequential tables? A combination is, e.g., means of travel to work by sex, by race/Hispanic origin. That's 3 variables. Sequential is. e.g., looking first at means of travel, then secondly at travel time, then sex of workers, then race/Hispanic origin of workers. That's four variables but they are not being cross-tabbed with one another. I agree that three is a reasonable limit in a *combination*. The data get stretched so thin that even 3 may be too many. In sequential, you should be able to look at as many variables as needed. Overall, it's still all about the number of cases. The more cases, the lower the MOE and vice versa. Patty Becker On Thu, Mar 14, 2013 at 3:13 PM, Steven Farber <Steven.Farber(a)geog.utah.edu>wrote: > Ed, Slide 39 (and a few preceding) lay the issue out on the table. It does > indeed have to do with covariance. The true equation for the SE of a sum of > random errors must include their covariances in the sum. I suppose when > the number of variables being added together is small, the omission of > covariances does not lead to a large difference in MOEs. But the estimation > of MOEs gets worse and worse, the more covariances that you leave out. > Since covariances are pairwise, the number being left out grows > exponentially with respect to the number of variables being added together. > > Nancy's email below: > > We were told to limit our aggregations to four items by Mark Asiala from > the ACS staff at our Annual California State Data Center meeting. It is > mentioned in his presentation slides online at > http://www.dof.ca.gov/research/demographic/state_census_data_center/meeting… Slide 39 > > There is other information in this presentation about the new sample frame > in the 2011 survey which may be interesting. > > Nancy Gemignani > California State Census Data Center > Demographic Research Unit > (916) 327-0103 ext 2550 > > Steven Farber, Ph.D > Assistant Professor > Department of Geography > University or Utah > http://stevenfarber.wordpress.com > > -----Original Message----- > From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] > On Behalf Of Ed Christopher > Sent: March-14-13 12:57 PM > To: ctpp-news(a)chrispy.net > Subject: Re: [CTPP] Working with County flow data > > Warning! This may ramble so if you do not care about the issue delete. > > Steve I am looking for specific references to the "limit of 3". I know I > have heard this many times and in fact tested it myself. Using data from > the Missouri State Data Center I got Tract data for the modes people use to > go work for my neighborhood Tract. With the Missouri data they had > published the total commuters calculated with a MOE along with the total > workers. I then went and pulled the 4 block groups for my neighborhood from > the census website. At the time the Missouri Data Center did not have Block > Group data published. I do not know if they have them now, I did not > check. While I could get the breakdown of the modes for the BGs, the table > did not have the total commuters as a subtotal with a corresponding MOE. I > figured I could just calculate my own adding up the 5 modes and do the > calculation. Before I went off to do this the scientist in me took over > and I tested the formula on the tract data just to see if I could replicate > the published MOE for the total n! > umber of commuters. I could not do it. Fortunately, Liang Long came to > my rescue and suggested that I just take the Total number of workers and > subtract those who work at home (both of which have MOEs) and try that. It > worked! I could replicate the published MOE. What this did was prove that > as you more variables to the mix the formula for calculating the MOE breaks > down. > > For what I was doing I was able to find a way of only working with two > variables but many times you can not. > > When I presented this at a transportation census conference in October of > 2011 several users in the "power users session" confirmed that they had > heard that 3 was the most variables you wanted to use at a time. I did > find this on the census site that says "limit the number of variables" > > http://www.census.gov/acs/www/Downloads/data_documentation/Statistical_Test… > > > A few days ago I talked with Elaine Murakami about this and she had the > perfect rule of thumb for me. Since the whole MOE thing is just an > approximation anyway "just take the largest MOE in the string of numbers > you are aggregating and use that". If you think about it, this does make > some mathematical and more importantly intuitive sense. I wish we could > get some statisticians to help out here. We need easy, quick to use methods. > > > Steven Farber wrote: > > I think I jumped the gun before when stating concerns over exploding > MOE's. > > > > Going back to the New York State Data Center document, you'll notice > that the MOE has increased in absolute terms when summing over areas, but > dropped in relative terms in comparison to the sum. > > > > So MOE has increased but the Coefficient of Variation has dropped. In > other words, our aggregated estimate is more precise than each of the > smaller area estimates. > > > > http://www.census.gov/acs/www/Downloads/handbooks/ACSResearch.pdf - > Appendix 3 contains all the calculations required. > > > > Ed, do you recall where you saw that this type of calculation should be > limited to 3 summands at a time? > > > > > > > > > > Steven Farber, Ph.D > > Assistant Professor > > Department of Geography > > University or Utah > > http://stevenfarber.wordpress.com > > > > -----Original Message----- > > From: ctpp-news-bounces(a)chrispy.net > > [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of liang.long(a)dot.gov > > Sent: March-12-13 10:18 AM > > To: ctpp-news(a)chrispy.net > > Subject: Re: [CTPP] Working with County flow data > > > > I can see why Census doesn't recommend do more than three variables at a > time. When you add 17 counties together, you get a much bigger area with > more households sampled. In theory, you should get a smaller MOEs compared > each individual county. But if you derive MOEs from those 17 counties, you > will get a much bigger MOEs, which is contradictory to the theory. > > > > > > ________________________________________ > > From: ctpp-news-bounces(a)chrispy.net [ctpp-news-bounces(a)chrispy.net] on > > behalf of Ed Christopher [edc(a)berwyned.com] > > Sent: Tuesday, March 12, 2013 11:15 AM > > To: ctpp-news(a)chrispy.net > > Subject: Re: [CTPP] Working with County flow data > > > > Thanks--I know the spread sheet allows you to recalculate MOEs for more > than three variables but I remember doing more than 3 a while back and I > was getting some wild MOEs. When I dug into it I found something in the > Census compass reports that said not to do more than three variables at a > time. I was hoping that someone figured out a way around this. > > > > Ed C > > > > On Mar 12, 2013, at 9:59 AM, "Hoctor Mulmat, Darlanne" < > Darlanne.Mulmat(a)sandag.org<mailto:Darlanne.Mulmat(a)sandag.org>> wrote: > > > > The New York State Data Center developed a Statistical Calculations Menu > that includes an option for computing the margin of error for the sum of > three or more estimates. See attached. > > > > Darlanne Hoctor Mulmat > > Applied Research Division - Criminal Justice/Public Policy San Diego > > Association of Governments > > 619-699-7326 > > > > From: > > ctpp-news-bounces(a)chrispy.net<mailto:ctpp-news-bounces(a)chrispy.net> > > [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of > > Ed.Christopher(a)dot.gov<mailto:Ed.Christopher(a)dot.gov> > > Sent: Tuesday, March 12, 2013 6:57 AM > > To: ctpp-news(a)chrispy.net<mailto:ctpp-news(a)chrispy.net> > > Subject: [CTPP] Working with County flow data > > > > Has anyone come up with some easy ways for collapsing and grouping > counties together using last week's county flow data and recalculating new > MOEs. I have so many counties that I want to group together that I am > looking for a quick way that can handle "lots" of counties. Another issue > I am struggling with is that we are always told not to group more than > three variables at a time or the formulas for calculating the new MOE do > not really work. This is particularly troublesome especially if I am > trying to group 17 counties together. What it comes down to is 9 different > calculations given that I can only group 3 counties at a time together. > Anyone figure out any short cuts or ways around this short of disregarding > the MOEs altogether? Given all the clustering that I am looking at using > the "cheat" sheets I am used to, I will be recalculating MOEs for weeks. > > > > > > Ed Christopher > > <StatisticalCalculationsMenu.xls> > > _______________________________________________ > > ctpp-news mailing list > > ctpp-news(a)ryoko.chrispy.net<mailto:ctpp-news(a)ryoko.chrispy.net> > > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > > > > _______________________________________________ > > ctpp-news mailing list > > ctpp-news(a)ryoko.chrispy.net > > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > > > > _______________________________________________ > > ctpp-news mailing list > > ctpp-news(a)ryoko.chrispy.net > > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > > > > -- > Ed Christopher > 708-283-3534 (V) > 708-574-8131 (cell) > > FHWA RC-TST-PLN > 4749 Lincoln Mall Drive, Suite 600 > Matteson, IL 60443 > _______________________________________________ > ctpp-news mailing list > ctpp-news(a)ryoko.chrispy.net > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > > _______________________________________________ > ctpp-news mailing list > ctpp-news(a)ryoko.chrispy.net > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > -- Patricia C. (Patty) Becker APB Associates/Southeast Michigan Census Council (SEMCC) 28300 Franklin Rd, Southfield, MI 48034 office: 248-354-6520 home:248-355-2428 pbecker(a)umich.edu

12 years, 5 months

Re: [CTPP] Working with County flow data

by Chu

Some covariance terms are positive and some are negative in most cases. How the number of variables affect the estimated MOE for the sum depends on how these positive and negative covariance terms add up. -----Original Message----- From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of Steven Farber Sent: Thursday, March 14, 2013 3:13 PM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Working with County flow data Ed, Slide 39 (and a few preceding) lay the issue out on the table. It does indeed have to do with covariance. The true equation for the SE of a sum of random errors must include their covariances in the sum. I suppose when the number of variables being added together is small, the omission of covariances does not lead to a large difference in MOEs. But the estimation of MOEs gets worse and worse, the more covariances that you leave out. Since covariances are pairwise, the number being left out grows exponentially with respect to the number of variables being added together. Nancy's email below: We were told to limit our aggregations to four items by Mark Asiala from the ACS staff at our Annual California State Data Center meeting. It is mentioned in his presentation slides online at http://www.dof.ca.gov/research/demographic/state_census_data_center/meeting… Slide 39 There is other information in this presentation about the new sample frame in the 2011 survey which may be interesting. Nancy Gemignani California State Census Data Center Demographic Research Unit (916) 327-0103 ext 2550 Steven Farber, Ph.D Assistant Professor Department of Geography University or Utah http://stevenfarber.wordpress.com -----Original Message----- From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of Ed Christopher Sent: March-14-13 12:57 PM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Working with County flow data Warning! This may ramble so if you do not care about the issue delete. Steve I am looking for specific references to the "limit of 3". I know I have heard this many times and in fact tested it myself. Using data from the Missouri State Data Center I got Tract data for the modes people use to go work for my neighborhood Tract. With the Missouri data they had published the total commuters calculated with a MOE along with the total workers. I then went and pulled the 4 block groups for my neighborhood from the census website. At the time the Missouri Data Center did not have Block Group data published. I do not know if they have them now, I did not check. While I could get the breakdown of the modes for the BGs, the table did not have the total commuters as a subtotal with a corresponding MOE. I figured I could just calculate my own adding up the 5 modes and do the calculation. Before I went off to do this the scientist in me took over and I tested the formula on the tract data just to see if I could replicate the published MOE for the total n! umber of commuters. I could not do it. Fortunately, Liang Long came to my rescue and suggested that I just take the Total number of workers and subtract those who work at home (both of which have MOEs) and try that. It worked! I could replicate the published MOE. What this did was prove that as you more variables to the mix the formula for calculating the MOE breaks down. For what I was doing I was able to find a way of only working with two variables but many times you can not. When I presented this at a transportation census conference in October of 2011 several users in the "power users session" confirmed that they had heard that 3 was the most variables you wanted to use at a time. I did find this on the census site that says "limit the number of variables" http://www.census.gov/acs/www/Downloads/data_documentation/Statistical_Test… A few days ago I talked with Elaine Murakami about this and she had the perfect rule of thumb for me. Since the whole MOE thing is just an approximation anyway "just take the largest MOE in the string of numbers you are aggregating and use that". If you think about it, this does make some mathematical and more importantly intuitive sense. I wish we could get some statisticians to help out here. We need easy, quick to use methods. Steven Farber wrote: > I think I jumped the gun before when stating concerns over exploding MOE's. > > Going back to the New York State Data Center document, you'll notice that the MOE has increased in absolute terms when summing over areas, but dropped in relative terms in comparison to the sum. > > So MOE has increased but the Coefficient of Variation has dropped. In other words, our aggregated estimate is more precise than each of the smaller area estimates. > > http://www.census.gov/acs/www/Downloads/handbooks/ACSResearch.pdf - Appendix 3 contains all the calculations required. > > Ed, do you recall where you saw that this type of calculation should be limited to 3 summands at a time? > > > > > Steven Farber, Ph.D > Assistant Professor > Department of Geography > University or Utah > http://stevenfarber.wordpress.com > > -----Original Message----- > From: ctpp-news-bounces(a)chrispy.net > [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of liang.long(a)dot.gov > Sent: March-12-13 10:18 AM > To: ctpp-news(a)chrispy.net > Subject: Re: [CTPP] Working with County flow data > > I can see why Census doesn't recommend do more than three variables at a time. When you add 17 counties together, you get a much bigger area with more households sampled. In theory, you should get a smaller MOEs compared each individual county. But if you derive MOEs from those 17 counties, you will get a much bigger MOEs, which is contradictory to the theory. > > > ________________________________________ > From: ctpp-news-bounces(a)chrispy.net [ctpp-news-bounces(a)chrispy.net] on > behalf of Ed Christopher [edc(a)berwyned.com] > Sent: Tuesday, March 12, 2013 11:15 AM > To: ctpp-news(a)chrispy.net > Subject: Re: [CTPP] Working with County flow data > > Thanks--I know the spread sheet allows you to recalculate MOEs for more than three variables but I remember doing more than 3 a while back and I was getting some wild MOEs. When I dug into it I found something in the Census compass reports that said not to do more than three variables at a time. I was hoping that someone figured out a way around this. > > Ed C > > On Mar 12, 2013, at 9:59 AM, "Hoctor Mulmat, Darlanne" <Darlanne.Mulmat(a)sandag.org<mailto:Darlanne.Mulmat(a)sandag.org>> wrote: > > The New York State Data Center developed a Statistical Calculations Menu that includes an option for computing the margin of error for the sum of three or more estimates. See attached. > > Darlanne Hoctor Mulmat > Applied Research Division - Criminal Justice/Public Policy San Diego > Association of Governments > 619-699-7326 > > From: > ctpp-news-bounces(a)chrispy.net<mailto:ctpp-news-bounces(a)chrispy.net> > [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of > Ed.Christopher(a)dot.gov<mailto:Ed.Christopher(a)dot.gov> > Sent: Tuesday, March 12, 2013 6:57 AM > To: ctpp-news(a)chrispy.net<mailto:ctpp-news(a)chrispy.net> > Subject: [CTPP] Working with County flow data > > Has anyone come up with some easy ways for collapsing and grouping counties together using last week's county flow data and recalculating new MOEs. I have so many counties that I want to group together that I am looking for a quick way that can handle "lots" of counties. Another issue I am struggling with is that we are always told not to group more than three variables at a time or the formulas for calculating the new MOE do not really work. This is particularly troublesome especially if I am trying to group 17 counties together. What it comes down to is 9 different calculations given that I can only group 3 counties at a time together. Anyone figure out any short cuts or ways around this short of disregarding the MOEs altogether? Given all the clustering that I am looking at using the "cheat" sheets I am used to, I will be recalculating MOEs for weeks. > > > Ed Christopher > <StatisticalCalculationsMenu.xls> > _______________________________________________ > ctpp-news mailing list > ctpp-news(a)ryoko.chrispy.net<mailto:ctpp-news(a)ryoko.chrispy.net> > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > > _______________________________________________ > ctpp-news mailing list > ctpp-news(a)ryoko.chrispy.net > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > > _______________________________________________ > ctpp-news mailing list > ctpp-news(a)ryoko.chrispy.net > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > -- Ed Christopher 708-283-3534 (V) 708-574-8131 (cell) FHWA RC-TST-PLN 4749 Lincoln Mall Drive, Suite 600 Matteson, IL 60443 _______________________________________________ ctpp-news mailing list ctpp-news(a)ryoko.chrispy.net http://ryoko.chrispy.net/mailman/listinfo/ctpp-news _______________________________________________ ctpp-news mailing list ctpp-news(a)ryoko.chrispy.net http://ryoko.chrispy.net/mailman/listinfo/ctpp-news

12 years, 5 months

Re: [CTPP] Working with County flow data

by Ed Christopher

Warning! This may ramble so if you do not care about the issue delete. Steve I am looking for specific references to the "limit of 3". I know I have heard this many times and in fact tested it myself. Using data from the Missouri State Data Center I got Tract data for the modes people use to go work for my neighborhood Tract. With the Missouri data they had published the total commuters calculated with a MOE along with the total workers. I then went and pulled the 4 block groups for my neighborhood from the census website. At the time the Missouri Data Center did not have Block Group data published. I do not know if they have them now, I did not check. While I could get the breakdown of the modes for the BGs, the table did not have the total commuters as a subtotal with a corresponding MOE. I figured I could just calculate my own adding up the 5 modes and do the calculation. Before I went off to do this the scientist in me took over and I tested the formula on the tract data just to see if I could replicate the published MOE for the total number of commuters. I could not do it. Fortunately, Liang Long came to my rescue and suggested that I just take the Total number of workers and subtract those who work at home (both of which have MOEs) and try that. It worked! I could replicate the published MOE. What this did was prove that as you more variables to the mix the formula for calculating the MOE breaks down. For what I was doing I was able to find a way of only working with two variables but many times you can not. When I presented this at a transportation census conference in October of 2011 several users in the "power users session" confirmed that they had heard that 3 was the most variables you wanted to use at a time. I did find this on the census site that says "limit the number of variables" http://www.census.gov/acs/www/Downloads/data_documentation/Statistical_Test… A few days ago I talked with Elaine Murakami about this and she had the perfect rule of thumb for me. Since the whole MOE thing is just an approximation anyway "just take the largest MOE in the string of numbers you are aggregating and use that". If you think about it, this does make some mathematical and more importantly intuitive sense. I wish we could get some statisticians to help out here. We need easy, quick to use methods. Steven Farber wrote: > I think I jumped the gun before when stating concerns over exploding MOE's. > > Going back to the New York State Data Center document, you'll notice that the MOE has increased in absolute terms when summing over areas, but dropped in relative terms in comparison to the sum. > > So MOE has increased but the Coefficient of Variation has dropped. In other words, our aggregated estimate is more precise than each of the smaller area estimates. > > http://www.census.gov/acs/www/Downloads/handbooks/ACSResearch.pdf - Appendix 3 contains all the calculations required. > > Ed, do you recall where you saw that this type of calculation should be limited to 3 summands at a time? > > > > > Steven Farber, Ph.D > Assistant Professor > Department of Geography > University or Utah > http://stevenfarber.wordpress.com > > -----Original Message----- > From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of liang.long(a)dot.gov > Sent: March-12-13 10:18 AM > To: ctpp-news(a)chrispy.net > Subject: Re: [CTPP] Working with County flow data > > I can see why Census doesn't recommend do more than three variables at a time. When you add 17 counties together, you get a much bigger area with more households sampled. In theory, you should get a smaller MOEs compared each individual county. But if you derive MOEs from those 17 counties, you will get a much bigger MOEs, which is contradictory to the theory. > > > ________________________________________ > From: ctpp-news-bounces(a)chrispy.net [ctpp-news-bounces(a)chrispy.net] on behalf of Ed Christopher [edc(a)berwyned.com] > Sent: Tuesday, March 12, 2013 11:15 AM > To: ctpp-news(a)chrispy.net > Subject: Re: [CTPP] Working with County flow data > > Thanks--I know the spread sheet allows you to recalculate MOEs for more than three variables but I remember doing more than 3 a while back and I was getting some wild MOEs. When I dug into it I found something in the Census compass reports that said not to do more than three variables at a time. I was hoping that someone figured out a way around this. > > Ed C > > On Mar 12, 2013, at 9:59 AM, "Hoctor Mulmat, Darlanne" <Darlanne.Mulmat(a)sandag.org<mailto:Darlanne.Mulmat(a)sandag.org>> wrote: > > The New York State Data Center developed a Statistical Calculations Menu that includes an option for computing the margin of error for the sum of three or more estimates. See attached. > > Darlanne Hoctor Mulmat > Applied Research Division - Criminal Justice/Public Policy San Diego Association of Governments > 619-699-7326 > > From: ctpp-news-bounces(a)chrispy.net<mailto:ctpp-news-bounces(a)chrispy.net> [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of Ed.Christopher(a)dot.gov<mailto:Ed.Christopher(a)dot.gov> > Sent: Tuesday, March 12, 2013 6:57 AM > To: ctpp-news(a)chrispy.net<mailto:ctpp-news(a)chrispy.net> > Subject: [CTPP] Working with County flow data > > Has anyone come up with some easy ways for collapsing and grouping counties together using last week's county flow data and recalculating new MOEs. I have so many counties that I want to group together that I am looking for a quick way that can handle "lots" of counties. Another issue I am struggling with is that we are always told not to group more than three variables at a time or the formulas for calculating the new MOE do not really work. This is particularly troublesome especially if I am trying to group 17 counties together. What it comes down to is 9 different calculations given that I can only group 3 counties at a time together. Anyone figure out any short cuts or ways around this short of disregarding the MOEs altogether? Given all the clustering that I am looking at using the "cheat" sheets I am used to, I will be recalculating MOEs for weeks. > > > Ed Christopher > <StatisticalCalculationsMenu.xls> > _______________________________________________ > ctpp-news mailing list > ctpp-news(a)ryoko.chrispy.net<mailto:ctpp-news(a)ryoko.chrispy.net> > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > > _______________________________________________ > ctpp-news mailing list > ctpp-news(a)ryoko.chrispy.net > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > > _______________________________________________ > ctpp-news mailing list > ctpp-news(a)ryoko.chrispy.net > http://ryoko.chrispy.net/mailman/listinfo/ctpp-news > -- Ed Christopher 708-283-3534 (V) 708-574-8131 (cell) FHWA RC-TST-PLN 4749 Lincoln Mall Drive, Suite 600 Matteson, IL 60443

12 years, 5 months

Re: [CTPP] Working with County flow data

by Gemignani

We were told to limit our aggregations to four items by Mark Asiala from the ACS staff at our Annual California State Data Center meeting. It is mentioned in his presentation slides online at http://www.dof.ca.gov/research/demographic/state_census_data_center/meeting… Slide 39 There is other information in this presentation about the new sample frame in the 2011 survey which may be interesting. Nancy Gemignani California State Census Data Center Demographic Research Unit (916) 327-0103 ext 2550 -----Original Message----- From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of Steven Farber Sent: Thursday, March 14, 2013 10:17 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Working with County flow data I think I jumped the gun before when stating concerns over exploding MOE's. Going back to the New York State Data Center document, you'll notice that the MOE has increased in absolute terms when summing over areas, but dropped in relative terms in comparison to the sum. So MOE has increased but the Coefficient of Variation has dropped. In other words, our aggregated estimate is more precise than each of the smaller area estimates. http://www.census.gov/acs/www/Downloads/handbooks/ACSResearch.pdf - Appendix 3 contains all the calculations required. Ed, do you recall where you saw that this type of calculation should be limited to 3 summands at a time? Steven Farber, Ph.D Assistant Professor Department of Geography University or Utah http://stevenfarber.wordpress.com -----Original Message----- From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of liang.long(a)dot.gov Sent: March-12-13 10:18 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Working with County flow data I can see why Census doesn't recommend do more than three variables at a time. When you add 17 counties together, you get a much bigger area with more households sampled. In theory, you should get a smaller MOEs compared each individual county. But if you derive MOEs from those 17 counties, you will get a much bigger MOEs, which is contradictory to the theory. ________________________________________ From: ctpp-news-bounces(a)chrispy.net [ctpp-news-bounces(a)chrispy.net] on behalf of Ed Christopher [edc(a)berwyned.com] Sent: Tuesday, March 12, 2013 11:15 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Working with County flow data Thanks--I know the spread sheet allows you to recalculate MOEs for more than three variables but I remember doing more than 3 a while back and I was getting some wild MOEs. When I dug into it I found something in the Census compass reports that said not to do more than three variables at a time. I was hoping that someone figured out a way around this. Ed C On Mar 12, 2013, at 9:59 AM, "Hoctor Mulmat, Darlanne" <Darlanne.Mulmat(a)sandag.org<mailto:Darlanne.Mulmat(a)sandag.org>> wrote: The New York State Data Center developed a Statistical Calculations Menu that includes an option for computing the margin of error for the sum of three or more estimates. See attached. Darlanne Hoctor Mulmat Applied Research Division - Criminal Justice/Public Policy San Diego Association of Governments 619-699-7326 From: ctpp-news-bounces(a)chrispy.net<mailto:ctpp-news-bounces(a)chrispy.net> [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of Ed.Christopher(a)dot.gov<mailto:Ed.Christopher(a)dot.gov> Sent: Tuesday, March 12, 2013 6:57 AM To: ctpp-news(a)chrispy.net<mailto:ctpp-news(a)chrispy.net> Subject: [CTPP] Working with County flow data Has anyone come up with some easy ways for collapsing and grouping counties together using last week's county flow data and recalculating new MOEs. I have so many counties that I want to group together that I am looking for a quick way that can handle "lots" of counties. Another issue I am struggling with is that we are always told not to group more than three variables at a time or the formulas for calculating the new MOE do not really work. This is particularly troublesome especially if I am trying to group 17 counties together. What it comes down to is 9 different calculations given that I can only group 3 counties at a time together. Anyone figure out any short cuts or ways around this short of disregarding the MOEs altogether? Given all the clustering that I am looking at using the "cheat" sheets I am used to, I will be recalculating MOEs for weeks. Ed Christopher <StatisticalCalculationsMenu.xls> _______________________________________________ ctpp-news mailing list ctpp-news(a)ryoko.chrispy.net<mailto:ctpp-news(a)ryoko.chrispy.net> http://ryoko.chrispy.net/mailman/listinfo/ctpp-news _______________________________________________ ctpp-news mailing list ctpp-news(a)ryoko.chrispy.net http://ryoko.chrispy.net/mailman/listinfo/ctpp-news _______________________________________________ ctpp-news mailing list ctpp-news(a)ryoko.chrispy.net http://ryoko.chrispy.net/mailman/listinfo/ctpp-news

12 years, 5 months

Re: [CTPP] Working with County flow data

by Steven Farber

I think I jumped the gun before when stating concerns over exploding MOE's. Going back to the New York State Data Center document, you'll notice that the MOE has increased in absolute terms when summing over areas, but dropped in relative terms in comparison to the sum. So MOE has increased but the Coefficient of Variation has dropped. In other words, our aggregated estimate is more precise than each of the smaller area estimates. http://www.census.gov/acs/www/Downloads/handbooks/ACSResearch.pdf - Appendix 3 contains all the calculations required. Ed, do you recall where you saw that this type of calculation should be limited to 3 summands at a time? Steven Farber, Ph.D Assistant Professor Department of Geography University or Utah http://stevenfarber.wordpress.com -----Original Message----- From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of liang.long(a)dot.gov Sent: March-12-13 10:18 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Working with County flow data I can see why Census doesn't recommend do more than three variables at a time. When you add 17 counties together, you get a much bigger area with more households sampled. In theory, you should get a smaller MOEs compared each individual county. But if you derive MOEs from those 17 counties, you will get a much bigger MOEs, which is contradictory to the theory. ________________________________________ From: ctpp-news-bounces(a)chrispy.net [ctpp-news-bounces(a)chrispy.net] on behalf of Ed Christopher [edc(a)berwyned.com] Sent: Tuesday, March 12, 2013 11:15 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] Working with County flow data Thanks--I know the spread sheet allows you to recalculate MOEs for more than three variables but I remember doing more than 3 a while back and I was getting some wild MOEs. When I dug into it I found something in the Census compass reports that said not to do more than three variables at a time. I was hoping that someone figured out a way around this. Ed C On Mar 12, 2013, at 9:59 AM, "Hoctor Mulmat, Darlanne" <Darlanne.Mulmat(a)sandag.org<mailto:Darlanne.Mulmat(a)sandag.org>> wrote: The New York State Data Center developed a Statistical Calculations Menu that includes an option for computing the margin of error for the sum of three or more estimates. See attached. Darlanne Hoctor Mulmat Applied Research Division - Criminal Justice/Public Policy San Diego Association of Governments 619-699-7326 From: ctpp-news-bounces(a)chrispy.net<mailto:ctpp-news-bounces(a)chrispy.net> [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of Ed.Christopher(a)dot.gov<mailto:Ed.Christopher(a)dot.gov> Sent: Tuesday, March 12, 2013 6:57 AM To: ctpp-news(a)chrispy.net<mailto:ctpp-news(a)chrispy.net> Subject: [CTPP] Working with County flow data Has anyone come up with some easy ways for collapsing and grouping counties together using last week's county flow data and recalculating new MOEs. I have so many counties that I want to group together that I am looking for a quick way that can handle "lots" of counties. Another issue I am struggling with is that we are always told not to group more than three variables at a time or the formulas for calculating the new MOE do not really work. This is particularly troublesome especially if I am trying to group 17 counties together. What it comes down to is 9 different calculations given that I can only group 3 counties at a time together. Anyone figure out any short cuts or ways around this short of disregarding the MOEs altogether? Given all the clustering that I am looking at using the "cheat" sheets I am used to, I will be recalculating MOEs for weeks. Ed Christopher <StatisticalCalculationsMenu.xls> _______________________________________________ ctpp-news mailing list ctpp-news(a)ryoko.chrispy.net<mailto:ctpp-news(a)ryoko.chrispy.net> http://ryoko.chrispy.net/mailman/listinfo/ctpp-news _______________________________________________ ctpp-news mailing list ctpp-news(a)ryoko.chrispy.net http://ryoko.chrispy.net/mailman/listinfo/ctpp-news

12 years, 5 months

Re: [CTPP] OMB Released the New Metropolitan and micropolitan areas

by Graham

That sounds right. Federal statistical agencies are to begin using new MSAs as soon as practical - but that will be a while. I was talking last week with a labor market statistician for our Minnesota BLS shop. She told me the first BLS stats with new MSA definitions will be the monthly employment (and unemployment) #s for January 2014. New MSAs will *not* be used by US BLS & State agencies sooner than that. --Todd Graham Todd Graham Principal Forecaster | Metropolitan Council | Regional Policy and Research todd.graham(a)metc.state.mn.us P. 651.602.1322 | F. 651.602.1674 390 North Robert Street | St. Paul, MN 55101 | metrocouncil.org/data -----Original Message----- From: ctpp-news-bounces(a)chrispy.net [mailto:ctpp-news-bounces(a)chrispy.net] On Behalf Of liang.long(a)dot.gov Sent: Wednesday, March 13, 2013 11:22 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] OMB Released the New Metropolitan and micropolitan areas Hi, Nancy As far as I know, the new MSA definitions will not be applied to ACS 2012, which will be released this year. My guess is that they may be actually applied to ACS 2013, which will be out in calendar year 2014. Since MSAs are based on counties, you can always aggregate counties for the new MSA definitions. Thanks, Liang ________________________________________ From: ctpp-news-bounces(a)chrispy.net [ctpp-news-bounces(a)chrispy.net] on behalf of Nancy Reger [Nreger(a)morpc.org] Sent: Wednesday, March 13, 2013 11:16 AM To: ctpp-news(a)chrispy.net Subject: Re: [CTPP] OMB Released tje New Metropolitan and micropolitan areas Liang, Do you know when the ACS will start using these new MSA delineations in the data reported? Thank you, Nancy Nancy Reger | nreger(a)morpc.org Deputy Director, Transportation | Mid-Ohio Regional Planning Commission T: 614.233.4154 | | F: 614.233.4254 111 Liberty Street, Suite 100 | Columbus, OH 43215

12 years, 5 months

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