The former chairman of the Council of Economic Advisers last night called for equality of opportunity in the American job and credit markets.

Arthur M. Okun, speaking in the second of his Godkin lectures, told a crowd of 150 people at the Science Center last night that equality in these areas would bring increases in both the equity and the efficiency of the American economy.

He said the American economy has performed efficiently, but that improvement is needed in the equality of income distribution.

Okun said in order to improve the equality of our income distribution, we must recognize that the race for income is not always fair because factors of family background and innate abilities give some a head start.

Okun's third and last lecture on "Equality and Efficiency: The Big Tradeoff' will be given tonight.

Okun was chairman of the Council of Economic Advisers during the Johnson Administration. He is now a fellow at the Brookings Institute.