Which PUMA definition (2000 or 2010) is applied to the 2010-12 ACS 3-Year File?

#1

The 2000 definition was applied to both the 2010 and 2011 single year files, but the 2010 definiiton was applied to the 2012 single year file. When these are combined, which definiiton is used? I am wondering if just the 2000 definiton was applied for the 3-year file or if there was sometype of hybrid definition used.

Release of 2009-2013 5yr PUMS
#2

The 2012 multi-year ACS files actually contain both the 2000 and 2010 Census based PUMAs, with the original survey year dictating which definition is used. So, as you pointed out, since the 2000 definition was applied to the 2010 and 2011 single year files, the 2000 PUMA codes and boundaries still apply to the 2010 and 2011 cases in the multi-year files. The variable MULTYEAR gives the original survey year for multi-year files in IPUMS-USA.

I hope this helps.