President Reagan's economic forecasts are overly optimistic and do not jibe with his policies, a Brookings Institution paper published yesterday says.

The paper, by Christopher Sims of the University of Minnesota, says that the Reagan program outlined in February likely would lead to another year of almost no growth in 1983, rather than the nearly 5 percent real growth now officially forecast.

The study shows "there was no way to achieve the forecast numbers . . . given the policies that were offered," Brookings economist George Perry said yesterday.

Using new statistical techniques, Sims says that the economy would likely grow by only 0.4 percent next year, after shrinking by 1 percent this year, assuming the Reagan program of budget cuts and tight money announced last February were carried out. The administration's latest forecasts, which senior officials have admitted are still overly optimistic, show growth of 1.7 percent this year and 4.4 percent next year.

Also in the latest volume of "Brookings Papers on Economic Activity":

* Economists Robert J. Gordon and Stephen R. King aim to measure how much output and employment are lost by fighting inflation. They conclude that reducing inflation by 5 percentage points over several years will lead to a loss of output worth 29 percent of gross national product in today's prices, or about $1 trillion. The authors believe such a cost outweighs the gain to the United States of a 5-percentage-point reduction in inflation.

* Recent major wage concessions are unlikely to have more than a small impact on overall wages and probably will not lead to a permanent improvement in wage inflation, according to Daniel B. Mitchell.