Robert J. Samuelson’s July 20 column, “America’s choppy, rising tide,” painted a prettier picture of American mobility than others may see. He correctly quoted the Pew Mobility Project report that most Americans’ (84 percent) income exceeds their parents’ income. As Mr. Samuelson wrote: “For the richest fifth, median income grew 126 percent from the late 1960s to the early 2000s, from $49,075 to $111,115. Among the poorest fifth, the median rose 74 percent, from $11,064 to $19,202.”

But consider that today many wives work when their 1960s counterparts did not, and the numbers don’t look as good. Pew omitted that the male median wage has declined slightly in the past 40 years. Moreover, the richest fifth’s median income today is $62,000 greater than the previous generation’s; that’s close to six times greater than the poorest, compared to 4.4 times a generation earlier. By this measure, inequality is 30 percent greater.

Arnold Packer, Baltimore

The writer was an assistant secretary of labor from 1977 to 1980.