The income gap between the nation's poorest and richest states is gradually closing, according to a conference Board analysis. In 1940, per capita income in the poorest one-fifth of the states was only 36 percent of that in the top fifth. By 1978 (the latest year for which official data are available), the average income of the bottom fifth had reached 72 percent of the top fifth.
Personal income consists mainly of wages, salaries and the income of the self- employed but also includes dividends, interest, and rents, and transfers such as social security and welfare.
The fastest income growth has been in the Southern and Western states. Average annual gains in per capita income from 1969 to 1978 were 9.9 percent in the Southwest, 9.7 percent in the Rockies, and 9.5 percent in the Southeast, compared with the national average of 8.8 percent. However, incomes in these states have traditionally been lower than in other parts of the country and this remains true despite the rapid growth. Per capita income in 1978 was over $7, 800 nationally but averaged about $6,800 in the Southeast and $7,500 in the Rockies and the Southwest.