To measure the impact of definitional differences between other surveys and the CPS, tabulations were produced to examine:
- Including lump sums or irregular retirement account withdrawals in income (SIPP and MEPS)
- Treating unmarried cohabiting individuals as a family rather than as unrelated individuals (MEPS and NHIS)
- Treating unrelated subfamily members as unrelated individuals (performed on the CPS to simulate ACS)
In addition, we used the flexibility afforded by monthly income, family composition and weights in SIPP to examine the impact of differences in the timing of family composition relative to the income reference period. We replicated the timing of family composition relative to the income reference period in the surveys (contemporaneous, end of year, following March, month by month up to 12 months after end of income year) and measure the resulting differences in the distribution of poverty status. Making these comparisons within a single data set ensures that the results reflect only the differences between methodologies and not differences in data.