American Community Survey – Reference at Newman Library

NYC Neighborhood Census Data Updates

I’ve received a few requests to do census data intros for spring courses, so I thought it would be a good time to mention this: I’ve updated the handout I’ve created for Finding NYC Neighborhood Census Data. It provides an overview of what neighborhoods are, what the census datasets are, and summarizes the main sources for the data. The handout is a PDF file that is embedded throughout the NYC Data Guide at http://guides.newman.baruch.cuny.edu/nyc_data.

I’ve also made updates to another PDF handout, the American Factfinder Tutorial, that’s embedded throughout the NYC Data and US Census Guides. I expect that I’ll have to update it again within the next month or so, as the Census is going to alter the AFF interface again to make it easier to use (based on user feedback).

The most pertinent, recent change to the Census: they are now releasing ZIP Code / ZCTA data on an annual basis as part of the 5-year American Community Survey ACS (previously, ZCTA data was only available via the decennial census). I’ve updated the Google Maps on the Neighborhoods tab of the NYC Data Guide so, when you click on a ZCTA, you can choose to look at the 2010 Census profile or one of the 4 ACS profiles from 2007-2011. The PUMA map has been updated to point to the latest 3-year ACS data (2009-2011) and the borough links to the most recent 1-year ACS data (2011).

New Census Resources for NYC Neighborhood Data

1. I’ve created a handout that summarizes the different neighborhood geographies, census datasets, and sources for finding neighborhood profiles and comparison tables. Much of the 2010 Census data is now available and the NYC Dept of City Planning has also released some new resources. The handout is available on the neighborhoods tab of the NYC Data Libguide as a PDF; it updates and replaces the Neighborhood FAQ page that was previously in the guide.

What’s the difference between the 2010 Census and the American Community Survey? What the heck is a PUMA and a ZCTA and what’s the difference? Where’s the best place to go get neighborhood census data? It’s all in the handout. The dataset, geography, and source you choose will vary based on the nature of the question and the relative importance of currency, size of geographic area, and variables needed.

2. I’ve created a new Google Map that lets you to click on ZIP Code Tabulation Areas (ZCTAs) within the city to open 2010 Census profiles directly from the Census Bureau’s American Factfinder. ZCTAs are statistical areas created by the Census Bureau to approximate USPS ZIP Codes. The map is also available on the neighborhoods tab of the NYC Data guide, directly below the PUMA Google Map (which you can use to get neighborhood profiles from the 2007-2009 American Community Survey). If viewing the map within the guide is too constraining, you can click the View Larger Map link directly below the map to get the full screen view.

2010 Census vs 2005-2009 ACS

The NY Times just released a new set of nationwide census map depicting some of the recently released data from the 2010 Census. Mapping the 2010 U.S. Census compliments the mapping site that the Times previously posted, Mapping America: Every City, Every Block, which used data from the 2005-2009 American Community Survey.

With both datasets side by side we can see important differences between them. If we look at census tract 68 in New York County (the tract where Baruch College is located), according to the 2010 Census there are 7,614 residents and the two largest groups are white (71%) and Asian (14%). If we look at this same tract according to the 2005-2009 American Community Survey, the estimate is 5,501 residents of whom 80% are white and 8% are Asian. What’s going on here? How can they be so different?

The 2010 Census is a snapshot, a one time count of what the total population was on April 1, 2010. The ACS on the other hand is a moving image, a rolling average based on five years of sample data between 2005 and 2009. They’re not going to be the same as they cover different time periods and are calculated using different methods. Also, the NY Times and most other publications often fail to report the confidence interval and the margins of error for the ACS estimates – for the 2005-2009 ACS, the estimate for Tract 68 is 5,501 residents, plus or minus 459 residents at a 90% confidence level.

Estimates tend to be more reliable as the population being surveyed increases or the geographic area increases in size. So you’ll get better estimates for total number of people than you would for a particular group, and you’ll get better estimates for a county then you would a census tract.

Which dataset should you use? For most of our students, who are often more interested in socio-economic variables like income and education, you’ll have to stick with the ACS. If they’re looking for population data (age, race, gender) and those socio-economic variables as well, they should get all of them from the ACS and not mix the two datasets together. The 2010 Census is not going to include ANY of the socio-economic data; these questions were cut and the ACS is the only place for these variables. But, if you have patrons who are interested in population change from 2000 to 2010 or they’re only interested in demographic variables, then the 2010 Census is the place to go.

I’ve included some maps from both mapping sites below that show tract 68 – they display the same data (total population and race) in a different format (2005-2009 ACS is a dot density map that shows race, 2010 Census is a shaded area map that shows total population change).

NY Times ACS 2005-2009 Map for NY County Census Tract 68

NY Times 2010 Census Map for NY County Census Tract 68

Finding current census data for NYC neighborhoods

Since this is a question that we frequently receive and there have been many changes to the census recently, I thought I’d provide some suggestions on how to answer it. Resources include the Census American Factfinder, the Social Explorer database, LibGuides, and Infoshare.

First, a new version of the American Factfinder has been launched. For this semester (Spring 2011) I’d suggest that you NOT use it – stick to the old version. The most recent datasets from the census are from the American Community Survey (ACS) and the new version doesn’t have ANY of the ACS data loaded yet. It will take several months before all of the ACS is added.

Second, I wouldn’t worry about looking for 2010 Census data yet. It’s going to take quite awhile before any neighborhood-level data is released, and once it is released it’s not going to be as comprehensive as it was in the past; the 2010 Census questionnaire was one of the shortest in US history. The ACS is replacing most of the detailed decennial census questions that were previously asked.

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Q. If I’m looking for data for a specific neighborhood, an overview or profile of that neighborhood, where should I look?

A. I’d suggest looking at the 3 year ACS (2007-2009) for public use microdata areas (PUMAs) which are decent for simulating NYC neighborhoods. There are 55 PUMAs in NYC:

1. Use this Google Map on the Neighborhoods tab of the NYC Data guide (http://guides.newman.baruch.cuny.edu/nyc_data) to click on a neighborhood, and go directly to a profile for that neighborhood on the census bureau website. Or

2. Use the Social Explorer database (http://newman.baruch.cuny.edu/search/databases.php), select the ACS 2007-2009, zoom in and click on the PUMA you want. You can then view a detailed demographic profile for that PUMA.

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Q. Hmmmmm… the PUMAs cover an area that’s larger than what I’m interested in. Are there smaller areas I can look at?

A. You can look at the 5 year ACS (2005-2009) for statistical areas called census tracts (the NY Times uses these in their Mapping America web map). Chances are these are smaller than what you would want to simulate a neighborhood , so you may have to choose several tracts and add the data together.

1. Use the Social Explorer’s map interface for the ACS 2005-2009 and select several census tracts by clicking on them or drawing a circle around an area. When you view the data report, you’ll see data for each tract you selected, and a totals column for all the areas (it sums them for you).

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Q. What if I want to compare several neighborhoods or all neighborhoods at once for a particular census variable? I’d like to build a comparison table.

A. The Social Explorer is the easiest choice, but to get access to ALL census tables you’d have to use the American Factfinder (Social Explorer only has a subset of census data):

1. You can use the Social Explorer to generate tables for PUMAs from the 3 year ACS or tracts from the 5 year ACS by clicking on individual areas or drawing a circle around them to create data tables.

2. You can go to the Census American Factfinder site directly (http://factfinder.census.gov/home/saff/main.html). Choose your dataset (ACS), Series (3 year 2007-2009 or 5 year 2005-2009), geography (pumas or tracts), and then the data table you want. When you choose geographies, you can easily select all PUMAs ranging from 03701 to 04114 to capture all PUMAs in the city.

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Q. I can’t find exactly what I’m looking for in the Census. Are there other sources?

A. Yes – take a look at the NYC Data subject (http://guides.newman.baruch.cuny.edu/nyc_data) guide for a list of alternatives. For example, the Furman Center at NYU publishes neighborhood profiles with lots of real estate data, and the NYC Dept of Health publishes profiles with health data.

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Q. Can I get current data for ZIP Codes?

A. Nope. ZIP Code data is not published as part of the ACS; it’s only available in the decennial census.

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Q. What about the Infoshare database on the library’s db page? Can’t I use that to get census data?

A. You can use Infoshare to build profiles or comparison tables for PUMAs (called sub-borough areas), Community Districts (59 areas slightly different than the 55 PUMAs), tracts, and “neighborhoods”, which are 292 areas designated by a city taskforce created by aggregating census tracts. The latter is the big selling point of this database; although it is difficult to ascertain what the boundaries of these neighborhoods are. My own personal bias is to use freely available resources whenever possible, especially when accessing a dataset that’s public domain to begin with. The American Factfinder is public domain, and there is a limited free version of Social Explorer available via the web. But in the end it’s up to you.

NY Metro Area ACS Geodatabase

We are now offering a value-added GIS census product through the Baruch Geoportal. The NY Metro ACS Geodatabase (NYMAG) contains geographic features and 2005-2007 American Community Survey data tables for the entire New York Metropolitan Area. Users will be able to download this geodatabase and use it with ArcGIS software to create thematic maps of census data at the public use microdata area (PUMA) geographic level. PUMAs are geographic areas that are useful surrogates for the city’s community districts or neighborhoods. Outside the city, PUMAs are subdivisions of counties.

The geodatabase, complete with user documentation and an example map, is available for download from the Baruch Geoportal at: http://www.baruch.cuny.edu/geoportal/data/nymag/.

Intermediate to advanced GIS users are the intended audience for this database. Hopefully we can roll out a simplified Google Maps interface for novices and non-GIS users sometime in the future. There are no access restrictions – anyone can download it, but will need access to GIS software in order to use it. The geodatabase is in Microsoft Access format which means that anyone with Microsoft Office can work with the data tables, but they won’t be able to use the geographic features without GIS software.

Many thanks to Clint Newsom who worked this summer as a GIS intern on this project – he is largely responsible for making it all happen. Clint is now back at the Information School at the University of Michigan, wrapping up his Info Studies degree.