As a beginning, this paper presents a comparison of the gross labor force flows as recorded in the SIPP and CPS during 1984. In that year, employment was growing rapidly and unemployment was dropping sharply in response to vigorous economic growth. In other words, we are examining flows occurring in a very strong phase of the business cycle. Our comparison shows that 1) the SIPP flows are smaller in general than the CPS flows and, 2) when the SIPP flows are balanced out, net changes in them are more consistent with the net changes in SIPP stocks than is the case with the CPS flows and stocks.