Top Coded and Bottom Coded Values by State

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The table below shows the top-code and bottom-code values by state. These top-codes and bottom-codes were derived based on the following rules:

  1. Age, travel time to work, and all base dollar amounts are top-coded using the state mean of all cases greater than or equal to the top-code state minimum value. The only exception to the top-code state minimum value is TAX which uses the top-code national minimum value. Income amounts which can have negative values (SEMP and INTP) are bottom-coded using the state mean of all cases less than or equal to the bottom-code state maximum value. Recodes of dollar amounts use the rounded top-coded/bottom-coded base dollar amounts without any additional top-coding/bottom-coding.
  2. Top-coded property taxes are further assigned to one of 68 categories.

Users should be aware that the IPUMS top- and bottom-codes diverge from those in the Census Bureau's documentation for two main reasons:

  1. The Census Bureau rounds its top-coded values before releasing the public-use data. For example, wage and salary income is rounded to the nearest $1,000 such that an actual top-coded value of $158,333 would become $158,000 in the public-use data. In most cases, these top-codes are off by no more than 0.1% from what would have been obtained if the Census Bureau had released the original, non-rounded top-codes. Monthly electricity and gas costs variables are rounded to the nearest $10. Because IPUMS multiplies these amounts by 12 to obtain the annual electricity and gas costs, this rounding error is similarly multiplied by 12. Still, most IPUMS utility top-codes diverge from the non-rounded utility top-codes by no more than 1%.
  2. While the Census Bureau documents top-codes for property taxes as actual dollar amounts, the public-use version of this variable is collapsed into sixty-nine categories.
Dataset IPUMS Original PUMS
1990 5% Excel --
1990 1% Excel --
2000 5% Excel Excel
2000 1% Excel Excel
2000 ACS Excel Excel
2001 ACS Excel Excel
2002 ACS Excel Excel
2003 ACS Excel Excel
2004 ACS Excel Excel
2005 ACS Excel Excel
2006 ACS Excel Excel
2007 ACS Excel Excel
2005-2007 3-Year ACS Excel *
2008 ACS Excel Excel
2006-2008 3-Year ACS Excel *
2009 ACS Excel Excel
2007-2009 3-Year ACS Excel *
2005-2009 5-Year ACS Excel *
2010 ACS Excel Excel
2008-2010 3-Year ACS Excel *
2006-2010 5-Year ACS Excel *
2011 ACS Excel PDF, CSV
2009-2011 3-Year ACS Excel *
2007-2011 5-Year ACS Excel *
2012 ACS Excel PDF, CSV
2010-2012 3-Year ACS Excel *
2008-2012 5-Year ACS Excel *
2013 ACS Excel PDF, CSV
2011-2013 3-Year ACS Excel *
2009-2013 5-Year ACS Excel *
2014 ACS Excel PDF, CSV
2010-2014 5-Year ACS Excel *
2015 ACS Excel PDF, CSV
2011-2015 5-Year ACS Excel *
2016 ACS Excel PDF, CSV
2012-2016 5-Year ACS Excel *
2017 ACS Excel PDF, CSV
2013-2017 5-Year ACS Excel *
*In the multi-year ACS PUMS files, the top- and bottom-codes can be found in the documentation for each data year that makes up the file. For example, in the 2005-2007 3-year ACS, the 2005, 2006, and 2007 original PUMS top- and bottom-code documentation files should each be referenced. This is not the case for the IPUMS multi-year datasets, as variables reporting dollar values have been inflated to dollars for the last data year (i.e., 2007 dollars for the 2005-2007 3-year file) resulting in top- and bottom- codes that differ from the single-year ACS documentation.

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