The general revenue-sharing program, which former President Nixon proposed in part as a way of moving more decision-making power to state and local governments, has tended to reinforce conventional patterns of local political power, according to a report by teh Brookings Institution.

Of 65 state and local governments studied, only 13 showed evidence of a shift in decision-making power, either among public officials or toward outside interest groups pressing for a say in how the money would be spent.

The 177-page study, second of a three-part series, also said the program, which now returns approximately $6.85 billion yearlt to cities, counties and states, has not increased enough to offset the effect of inflation since the program began in 1972.

By fiscal 1979, it said, the value of money dispensed under revenue sharing will have shrunk 17 per cent, from $5.31 billion in 1972 to $4.4 billion once the effect of inflation is factored in.

The study also agrees with civil rights critics who have charged that anti-discrimination provisions of the program are inadequate. Those provisions, which supposedly forbid revenue-sharing funds to be spent on programs that discriminate, had no effect in all but six of the governments studied. And in five of those six, the report said, they had little effect.

Richard P. Nathan and Charles F. Adams Jr., authors of the study, emphasized that the effects produced by revenue-sharing money vary widely, depending on the kinds of problems the local governments face, and how well their administrative machinery is run.

One example they cite is St. Louis, which distributed revenue-sharing funds in 1973 "in a log-rolling fashion after extensive consultations with neighborhood groups, and a variety of capital improvement projects around and city were funded."

By 1976, however, "an already troubled fiscal sitration for the city worsened because of inflation and recession, and . . . revenue-sharing funds simply went into the operating budget to maintain existing programs."