Educational attainment data VS CPS ASEC

Hi everyone!

Has anybody looked into this apparent statistically significant difference between the two surveys on educational attainment data?

2020 CPS counts a total of 113381 thousand 18+ civilian noninstitutionalized population with at least an associates degree, out of a total 252117, so ~45% in share.

Estimate for the same scope using 2020 5-years ACS PUMS is 97417 out of 253296, or ~38%.

The discrepancy is even more pronounced for only doctoral degree holders, where CPS estimates 4.7M vs ACS 3.2M, a nearly 50% higher number for the former.

Checking both survey's questionnaires, the question for educational attainment is essentially identical and reasonably unambiguous. What would be some factors leading to this rather stark discrepancy?

Really appreciate it if anyone could shed some light for me!

Sincerely,

Michael

Best,