Conduent Healthy Communities Institute

Which geography should I use?

Some data is only available at the state or county level; however, when data is available at sub-state or county level geographies (e.g., city, zip code, census tract), it can be difficult to choose which one is right for your data needs. Conduent Healthy Communities Institute suggests following these guidelines for finding and using credible data. In addition, please see below for pros and cons to help you select the best geography for your purpose. 

Geography Pros Cons
Zip Code/Zip Code Tabulation Area (ZCTA) 


  • May mirror neighborhoods 
  • Zip codes are recognizable to most local residents
  • Zip codes are created by the Postal Service; zip codes may change from year to year and vary in size (square mileage and population)
  • ZCTAs are created by the Census Bureau to approximate postal zip codes in each census tract 
  • For more information, click here 
  • Limited data by subgroup, such as race and/or gender 

Census Tract 

  • Suitable for trend analysis as boundaries change infrequently 
  • Relatively similar in population size (~2000 people) 
  • Every census tract is connected to a single county 
  • May be more helpful when providing data for policy decisions 
  • Mapping may become tedious 
  • Collecting data at this level may be difficult as most individuals do not know their census tract ID 
  • Limited data by subgroup, such as race and/or gender 
  • Does not include rural areas 
City/Census Place/Metro Area
  • Suitable for city and/or municipal planning decisions 
  • Helpful to compare within state and to other state’s cities and/or metro areas 
  • Does not include rural areas
  • Suitable for trend analysis as boundaries change infrequently 
  • Standard geographical unit for various data topics 
  • Data include more nuanced characteristics, such as race, ethnicity, gender, or age 
  • Size and population varies within states and across states 


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