MOSCOW, FEB. 7 -- A Soviet economist well-known here for his support of many free-market ideas has called for an understanding of the economy that is a radical departure from orthodox Marxist-Leninist ideology and practice.

Nikolai Shmelyov, who has demanded in the past that the Soviet Union lose its "ideological virginity," said in an interview published in the current issue of the Moscow News, "We have to introduce into all spheres of our social life the understanding that all that is economically ineffective is immoral, and all that is effective is moral."

In the Soviet Union, where the most basic personal economic problem is not so much lack of savings as the lack of much of quality to spend it on, Shmelyov's ideas are aimed at generating an increase in scarce goods and services.

He said that low interest rates for personal savings discourage people from making long-term investments in banks. If that were to change, he said, banks could finance new businesses and make more goods and services available to the people.

"The population keeps considerable sums not in savings banks but in piggy banks at home," he said.

Shmelyov also said that if enterprises were permitted to sell shares and people allowed to invest in them at a "sufficiently high" return rate" of 7 to 10 percent, state farms and industries would be able to raise "tens of billions of rubles."

He said the Soviet Union's intentions about price reforms are still "vague" and that the present structure of prices, which is set by state planners rather than determined by the market, is a "kingdom of distorting mirrors." When prices are determined, he said, "he who shouts louder gets more."

The price system, Shmelyov said, creates economic "absurdities" that have damaged the economy. He noted that, since the price of land has "never been considered in our country, for whole decades we were convinced that the cheapest form of energy is produced by hydroelectric power stations." That, he said, has ruined millions of acres of fertile land.

The Soviet Union should lower taxes on western businesses trying to establish joint ventures with the U.S.S.R., he said. "Just try to put yourself in the place of an American businessman," Shmelyov explained. "If, in the U.S.A., he pays 34 percent profits tax, somewhere in Southeast Asia 20 or 25 percent, and in the Soviet Union 44 percent, is there any sense in him investing any money in our country?"

Shmelyov proposed fixing the exchange rate of the ruble, saying "now there are actually more than 2,000 such rates" -- and called for an end to the state's subsidies on numerous goods.

Shmelyov cautioned that perestroika, Mikahil Gorbachev's economic restructuring program, is full of "difficulties and drawbacks."