The end of December is a time when soothsayers, savants and visionaries tell us what to expect the following year. Rarely are they right, but no one remembers what they predicted anyway.

The World Future Society is telling us, for example, that biotechnology will make it possible to produce orange juice without either the orange or the tree.Not to be outdone, the Socio-Economic Research Institute of America is proclaiming that sex will be in next year and abstinence will be out. This apparently is based on the dubious premise that abstinence was in this year and sex was out.

Economists are evasive about 1991. They don't know whether we're going to have a war in the Persian Gulf, so they aren't sure what the price of oil will be. Maybe $20 a barrel. Maybe $50.

Mostly, economists talk about a "mild" recession, which means your neighbor lost his job but you're still working.

In truth, no one knows what 1991 will bring, but few are reluctant to express an opinion.

In the spirit of off-the-wall forecasting, here are some things we can expect from the U.S. economy in 1991:

- War in the Persian Gulf will be averted, driving down the price of oil and saving the country from a severe recession.

- The average salary of professional baseball players will exceed the average salary of the chief executives of major corporations.

- Home sellers in trendy cities will stop asking $399,000 for a modest, three-bedroom house that cost $48,000 in 1973. They will ask $349,000 and accept $219,000.

- So many women will join country clubs that Ladies Day on the golf course will be eliminated.

- The price of kiwi fruit at the supermarket will drop from two for 79 cents to two for 69 cents.

- Toothpaste in stand-up plungers will replace toothpaste in tubes in millions of American homes.

- Liquid soap will gain market share.

- Nearly 200 banks will fail. More than 200 savings and loans will fail. The distinction between banks and S&Ls will disappear.

- Federal budget deficits will set new records, but budget analysts will point out that deficits are increasing at a decreasing rate.

- Gasoline prices will come down and car sales will go up.

- Tuition costs at colleges and universities will rise an average of 6 percent to 8 percent. Colleges will say students want quality, and that's what they're going to get.

- The unemployment rate will reach 6.5 percent, then fall back to 5.5 percent as the economy perks up next summer and fall.

- President Bush will continue to push for a reduction in the capital gains tax. Congress will ignore him.

- No one will lend money to any developer who says he wants to build a new office building.

- The cost of medical care will rise 10 percent to 12 percent.

- Americans will complain about high taxes, poor bus service, corrupt politicians, air pollution, rude children, foreign aid and the fact that it now costs 30 cents to buy a 25-cent stamp.