For one important set of data, namely, the data on unemployment and employment collected by the Census Bureau in its monthly Current Population Survey (CPS), some information on nonsampling error is available that can be used to evaluate the regularly reported labor force figures. The paper is concerned with the nonsampling error that relates specifically to measurement, or response bias (the bias resulting from the interview and enumeration process itself). It examines and tabulates the extent of the response bias and its effect on national estimates of unemployment and employment. Unemployment rates corrected for this bias are estimated and compared with official unemployment rates. Cyclical and secular differences between official and bias-adjusted estimates of unemployment are noted, and the alternative unemployment rates are related to such cyclically sensitive variables as GNP (Gross National Product) gap, wage rates, and labor force participation rates. Census reinterviewing data, up to now unexploited, contain new, potentially valuable economic information. The data indicates that when the official unemployment rate is adjusted, it is consistently and significantly higher, with the gap between the unadjusted and the adjusted rate widening in the most recent quarters. The reinterview data also indicate that the CPS consistently understates total employment. (Author/LH)