An increase in the number of households headed by women since the late 1960s has led to a rise in the poverty rate for families with children, according to a study by Congress' Joint Economic Committee.

During the same period, however, there have been income advances among two-parent black families and working black wives, according to the study.

The report said that between 1973 and 1984, declines in average real income for households headed by women was greater than that for two-parent families, and that average real incomes for families headed by women were lower in 1984 than in 1967.

Additionally, between 1967 and 1984, income inequality increased, with the top 40 percent of families gaining income, while those in the bottom 40 percent saw their incomes decline, the study said. One hindrance to income growth was the rise in personal tax rates, the study added.

"While the economy has grown rapidly since the 1982-1983 recession, mean family income in 1984 was still below the 1973 level," according to the study. "And even if income continues to grow as rapidly as it has in the last two years, there is no indication that the trend toward increased inequality has been reversed."

The study focused much attention on the increasing numbers of households with children headed by women, which was a major reason for the worsening of poverty for many families.

"At the same time that the economic position of female-headed families was declining relative to that of two-parent families, their relative numbers were increasing among whites, blacks and Hispanics," the study said.

It also found that the income gaps between black two-parent families and their white counterparts and between black and white families headed by women had narrowed since 1967.

However, the total black-white income ratio among families with children was unchanged "because of the larger shift for blacks than whites toward female-headed families," the study said.

Poverty for all persons living in families with children increased rapidly between 1979 and 1984, the study said.

"Black two-parent families were the only group to deviate much from this trend" because their 1984 poverty rate of 19.3 percent "was substantially below" their rate in 1967 of 31.3 percent, the study said.

"While poverty rates decreased for black two-parent and female-headed families between 1967 and 1984, they increased for white two-parent and female-headed families," the study said. "Nonetheless, in 1984, blacks were still much more likely than their white counterparts to be poor.

"And as with family incomes, the greatest differences in poverty rates were between two-parent and female-headed families."

The study also gave reasons for the increase in poverty for families with children since 1967, despite the rapid growth in government programs for the poor. The study suggested that a larger proportion of families were headed by women who have above-average poverty rates and earnings of family heads decreased.

The study also said that "a large and growing proportion" of government transfer payments were received by the elderly.

The study is the third in a series released by the Joint Econonomic Committee on American family living standards.