Federal tax and spending incentives for research and innovation are not very effective and could be designed better, according to a report by the Congressional Budget Office.

The report, released recently, said the current tax credit for research and development can actually discourage research under some circumstances. And low effective tax rates on capital gains -- profits from the sale of an asset -- have less influence than do market forces in encouraging venture-capital investment, the report said.

A tax preference permitting tax shelters for those who invest in research, however, "provides a strong incentive for new projects," the report said. And direct federal spending accounts for "significant levels of R&D support" to high-technology industries, although its effectiveness is hard to assess.

The debate over how much tax breaks encourage innovation is a politically sensitive one at the moment. President Reagan's proposed tax overhaul, now pending in Congress, calls for renewal of the R&D credit and for continuation of a capital-gains tax rate lower than the rate on ordinary income.

The Treasury Department's first tax-revision proposal, however, called for doing away with the distinction while indexing the value of capital assets to inflation. The proposal's authors used some of the same arguments employed by the non-partisan CBO.

"The government already is spending large sums to enhance the competitive position of high-technology industries, although the effectiveness of many of its programs is open to question," the report said.

One of the leading spokesmen for the high-tech lobby responded to the conclusions of the report by calling it "dumb."

"My reaction is that this is the typical kind of drivel we tend to get from the green eye-shade types who constitute the federal bureaucracy," said John M. Albertine, president of the American Business Conference, an organization of high-growth companies.

"I wish the Congressional Budget Office would hire some people who are entrepreneurs and get rid of those academic economists. Every venture capitalist I've talked to thought the capital-gains tax reduction in 1978 was extremely helpful to their ability to raise venture capital."

A study by the ABC found that the cost of capital in the United States is higher than that of most other nations, Albertine said, partly because U.S. trading partners finance new investment more with debt and U.S. firms use more equity offerings.

Under current law, 60 percent of capital gains are not subject to tax. Because the top personal income tax rate is 50 percent, the maximum capital gains rate today is 20 percent.

Under the Reagan plan, the exclusion would be dropped to 50 percent. But because the top rate on ordinary income would fall to 35 percent, the top capital-gains rate would be 17.5 percent, lower than it is now.

Representatives of high-tech industries, such as Albertine, point to past reductions in the capital-gains rate to make their point that innovation and investment are enhanced with lower capital-gains rates.

The report says, however, that other factors also are responsible. Low tax rates can't create the demand for high-tech products, the report says; the market must do that. It points out that pension funds, endowments, foundations and foreign investors -- none of which are subject to U.S. taxation -- account for more than half of all venture capital.