Trends in the Transitory Variance of Male Earnings
利用1970-2004年美国收入动态面板研究数据，发现男性收入暂时性方差在1970年代初开始上升，至1980年代中期后维持高位，其增长解释了截面方差总上升的31%-49%。
We estimate the trend in the transitory variance of male earnings in the U.S. using the Michigan Panel Study of Income Dynamics from 1970 to 2004. Using an error components model and simpler but only approximate methods, we find that the transitory variance started to increase in the early 1970s, continued to increase through the mid-1980s, and then remained at this new higher level through the 1990s and beyond. Thus the increase mostly occurred about thirty years ago. Its increase accounts for between 31 and 49 percent of the total rise in cross-sectional variance, depending on the time period.