Expect tomorrow’s jobs report for January to indicate that the economy “added” between 250,000 and 300,000 jobs. Also expect jobs growth in the spring of 2013 to be disappointing. These expectations have nothing to do with budget negotiations in Washington, the impact of austerity measures in the Eurozone, or corporate earnings reports. The pattern of strong employment growth in January followed by disappointing payroll reports in the spring is the result of the BLS seasonal adjustment procedure.
One year ago the BLS reported that nonfarm payroll increased by 275,000 between December 2011 and January 2012 — the largest increase in employment since the recession (excluding May 2010 when hundreds of thousands of seasonal Census workers were hired). In fact, nonfarm payroll decreased by 2.67 million employees, but that decline was much smaller than the BLS statistical model projected.
The BLS seasonal adjustment procedure is a moving average process, which means that seasonal factors change over time. The BLS seasonal factors in January 2011 and January 2012 were unusually large because they reflected a historic decline of 3.7 million jobs between December 2008 and January 2009. The BLS X-12 ARIMA model for seasonal adjustment viewed this massive decline in employment as a signal that the “January effect” in payroll employment had become more pronounced. The procedure requires that future January’s would have larger projected employment declines. To be clear, a larger “January effect” is measured relative to other months of the year. If the new seasonal factors add 100,000 more jobs in January compared to the previous factors, a comparable number of jobs will be subtracted from other months of the year. Hence bigger “January effects” mean smaller payroll gains in other months, most notably the spring.
The data from last January suggest that it was a particularly deep recession, and not changing seasonal factors, that accounted for the steep employment decline four years ago. The legacy of the 2008-2009 decline is likely to still have an impact on BLS seasonal factors, but not by as much as in 2011 and 2012. Nonetheless, it would not be surprising to see surprisingly strong job growth of 275,000 in tomorrow’s report, and weaker than expected growth in April and May.