Part-Time for Economic Reasons: Measuring Involuntary Underemployment

Workers part-time for economic reasons are those employed part-time (fewer than 35 hours per week) who want full-time work but cannot find it because of inadequate business demand. The U.S. Bureau of Labor Statistics (BLS) tracks this group separately because they represent true labor slack: someone with a job but forced into reduced hours. They feed into the U-6 unemployment rate, a broader measure than the headline unemployment-rate that captures both joblessness and involuntary underemployment.

Definition and Measurement

The BLS defines someone as part-time for economic reasons if they meet three criteria: (1) employed part-time (1–34 hours worked in the reference week), (2) want full-time work, and (3) are part-time because of economic constraints rather than choice (employer cut hours, slack demand, or inability to find full-time work). This last point is critical—someone working part-time because they prefer to (caring for family, in school, semi-retired) does not count as part-time for economic reasons.

The data comes from the Current Population Survey (CPS), a monthly household survey of about 60,000 U.S. households. Each household reports employment status and hours worked. If someone reports working 25 hours in the reference week and says “I want a full-time job but my employer reduced my hours,” they are coded as part-time for economic reasons. If they say “I chose part-time while I finish my degree,” they are not, even if they work 20 hours.

The Business Cycle and Cyclical Slack

Part-time for economic reasons moves dramatically with the business-cycle. In healthy expansions, this group shrinks to around 2–3% of the total employed workforce, as employers extend hours and hire more full-time staff. During recessions, the share balloons to 5–8% or higher, as firms reduce operating hours and shift workers to part-time to preserve payroll flexibility.

The COVID-19 recession of March–April 2020 was extreme: part-time for economic reasons jumped from 3.5 million to 9.2 million workers within two months—a 163% surge—as hospitality, retail, and other contact-intensive sectors shut down and cut hours. The recovery was also rapid: by mid-2021, the measure had fallen back to pre-pandemic levels, reflecting quick rehiring and hour restoration.

The predictable cyclical pattern makes this measure useful for Fed officials and investors evaluating true slack. Headline unemployment-rate captures joblessness but ignores people forced into part-time work. Someone working 20 hours/week at minimum wage while seeking 40 hours/week is unemployed in spirit (income-constrained, job-seeking) but not in the headline count.

Relationship to U-6 Unemployment

The U-6 unemployment rate is the broadest official measure the BLS publishes. It includes:

• Unemployed (jobless and actively seeking work)
• Part-time for economic reasons
• Marginally attached (want work, not actively seeking)
• Discouraged workers (stopped looking, believe no jobs available)

U-6 is typically 2–3 percentage points higher than the headline unemployment-rate, because it captures involuntary part-time workers. In April 2020, U-6 reached 20.2% while headline unemployment was 14.7%—the 5.5-point gap reflects the enormous involuntary part-time surge.

The Federal Reserve watches both measures. In a weak labor market, headline unemployment might fall while part-time for economic reasons rises, signaling fake progress: employers are rehiring but offering shorter hours. In a tight market, both fall together, showing genuine job creation and hour expansion.

Duration and Sectoral Patterns

Some industries have structural part-time work (retail, food service, hospitality) where employers cap hours to avoid benefit obligations. During demand surges (holiday shopping, summer tourism), employers ask part-timers to work more hours voluntarily. During downturns, they cut hours and shift to pure part-time. Part-timers in these sectors are sensitive to demand swings.

Other industries (professional services, manufacturing) have more stable full-time roles, but recessions still push marginal workers into part-time shifts. Manufacturing in particular relies on temporary layoffs (unemployment with recall rights) and hour reductions to manage downturns without firing.

The duration of involuntary part-time work varies. Some are temporary: a restaurant worker furloughed for 4 weeks during a health crisis. Others last months or years: a retail clerk whose hours never fully return as e-commerce eats market share. Long-term involuntary part-time workers—those stuck at reduced hours for 6+ months—represent deeper structural slack and are a concern for policymakers focused on underemployment, not just unemployment.

Policy and Interpretation

The existence of millions of involuntary part-timers affects wage dynamics. Workers forced to work fewer hours often have less bargaining power and accept smaller raises. As involuntary part-time employment falls during recoveries, workers can more easily seek full-time roles, reducing the supply of available part-timers and lifting wages for part-time positions.

Policymakers debate how to weight headline unemployment vs. U-6. The Federal Reserve, targeting maximum employment, increasingly focuses on broader labor market slack measures including part-time for economic reasons. If headline unemployment is 4% but part-time for economic reasons is 6%, true slack is higher, and the Fed might be less aggressive raising rates.

Some economists argue that part-time for economic reasons understates involuntary underemployment, because the survey captures only stated preferences. A worker willing to work full-time but discouraged from job-searching is not counted as part-time for economic reasons; they may exit the labor force entirely. This suggests the BLS measures might undercount true slack in weak labor markets.

Real-World Example: 2008–2009 Financial Crisis

In December 2008, part-time for economic reasons surged to 8.8 million workers—6.4% of employed workers. Many were construction workers (residential building collapsed) and retail workers (consumer demand evaporated). As firms stabilized and demand recovered from 2010 onward, this group fell steadily, reaching 4.4 million (2.6% of employed) by July 2019, just before COVID. This 4+ year decline reflected a genuine tightening of labor markets, with employers confident enough to move workers to full-time and hire additional full-timers.

This sustained reduction was one reason Fed officials felt comfortable raising rates gradually in 2016–2018: not only was headline unemployment low, but underemployment was falling, signaling that true slack was being absorbed.

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