Trends in the Transitory Variance of Male Earnings: Methods and Evidence

Area of Science:

• Economics
• Econometrics
• Labor Economics

Background:

• Understanding earnings inequality trends is crucial for economic policy.
• Previous research has highlighted increasing wage gaps, but the role of transitory income fluctuations requires further investigation.

Purpose of the Study:

• To estimate the trend in transitory variance of male earnings in the U.S. from 1970 to 2004.
• To quantify the contribution of increased transitory variance to overall earnings inequality.

Main Methods:

• Utilized data from the Michigan Panel Study of Income Dynamics (1970-2004).
• Employed an error components model and simpler approximation methods for variance estimation.

Main Results:

• Transitory variance of male earnings began rising in the early 1970s, continuing through the mid-1980s.
• This elevated level of transitory variance persisted through the 1990s and beyond.
• The increase in transitory variance explains 31-49% of the rise in cross-sectional earnings variance.

Conclusions:

• The primary increase in male earnings transitory variance occurred approximately thirty years prior to the study period's end.
• Changes in transitory income components are a significant driver of overall earnings inequality trends.