Let's take a close look at Friday's employment report numbers on Full and Part-Time Employment. Buried near the bottom of Table A-9 of the government's Employment Situation Summary are the numbers for Full- and Part-Time Workers, with 35-or-more hours as the arbitrary divide between the two categories. The source is the monthly Current Population Survey (CPS) of households. The focus is on total hours worked regardless of whether the hours are from a single or multiple jobs.

The Labor Department has been collecting this since 1968, a time when only 13.5% of US employees were part-timers. That number peaked at 20.1% in January 2010. The latest data point, over five years later, is only modestly lower at 18.3% last month. If the pre-recession percentage is a recovery target, we're only about half-way there.

Here is a visualization of the trend in the 21st century, with the percentage of full-time employed on the left axis and the part-time employed on the right. We see a conspicuous crossover during the Great Recession.

Since February of this year, the two cohorts have been oscillating in a narrow range around the crossover point.

The Impact of the Great Recession

Here is a closer look since 2007. The reversal began in 2008, but it accelerated in the Fall of that year following the September 15th bankruptcy of Lehman Brothers. In this seasonally adjusted data, the reversal peaked in January of 2010.

A Closer Look at the Core Workforce, Ages 25-54

The two charts above are seasonally adjusted and include the entire workforce, which the CPS defines as age 16 and over. A problem inherent in using this broadest of cohorts is that it includes the population that adds substantial summertime volatility to the full-time/part-time ratio, namely, high school and college students. Also the 55-plus cohort includes a subset of employees that opt for part-time employment during the decade following the historical peak earning years (ages 45-54) and as a transition toward retirement.