Real average weekly earnings fell by 0.1 percent from December to January after seasonal adjustment, according to preliminary data released by the Bureau of Labor Statistics of the U.S. Department of Labor.

A 0.3 percent increase in average hourly earnings was offset by a 0.3 percent increase in the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W). Average weekly hours were unchanged.

Data on average weekly earnings are collected from the payroll reports of private nonfarm establishments. Earnings of both full-time and part-time workers holding production or nonsupervisory jobs are included. Real average weekly earnings are calculated by adjusting earnings in current dollars for changes in the CPI-W.

Average weekly earnings rose by 2.7 percent, seasonally adjusted, from January 2008 to January 2009. After deflation by the CPI-W, average weekly earnings increased by 3.4 percent. Before adjustment for seasonal change and inflation, average weekly earnings were $608.32 in January 2009, compared with $593.07 a year earlier.