A note on the unemployment figures released earlier this morning by the Bureau of Labor Statistics (BLS), reporting the results of a January survey of U.S. households: The seasonally adjusted unemployment rate fell from 9.4 percent in December to 9.0 percent last month, a healthy improvement. On the other hand, before seasonal adjustment, the unemployment rate rose from 9.1 percent in December to 9.8 percent in January. Raw data that are not seasonally adjusted show that the number of unemployed Americans rose by 940,000, while the number employed fell by 1,560,000. New adjustments for population changes, introduced by the BLS this month, affected these numbers by an amount that is possibly very large and that is not yet known to me. This latter problem probably affects raw numbers more than the overall unemployment rate. The seasonally unadjusted numbers used in this blog post can be found in table A-1 of the recent economic news release from the BLS.