Are housing prices going to be seriously deflated? Should you sell your house now and rent before the bloom is taken off your housing investment? In short, should you take the money and run?

Peter Treadway, vice president and chief economist of the Federal National Mortgage Association, recently answered all three questions with a resounding "no."

As Treadway, a Federal National Mortgage Association economist, sees the housing market, prices may not keep up with inflation for the next year but "in the longer run, prices for the right types of housing will once again rise as fast as, or faster, than inflation."

Pessimists are preoccupied with a notion that "house prices have rocketed upwards in a speculative frenzy which will ultimately prove its own undoing," Treadway charged in a recent speech to the National Economist Club here. The FNMA economist sees the housing market as being in a position similar to that in 1975, "a period just before the last housing-price boom."

He pointed out that inventories of unsold new house are relatively low, and that housing production has been low for nearly two years. "There just is no large overhand of new housing inventory," he emphasized, explaining that builders remember the housing problems of 1973-74 and do not build ahead of sales. He also said the homeowner vacancy rate is still relatively low and the rental housing vacancy rate is at an all-time low point.

As do many other housing observers, Treadway bases his confidence in the stability of housing prices on demographics. He cites continued growth in the national population, the maturation of the baby-boom generation born in the 1950s and 1960s, the rise in the number of working women who can afford to buy their own houses or become part of a two-income household that can buy more housing.

He also contends that affluent senior cizitens have a "very high propensity to maintain separate households."

In reviewing the reasons for the current slowdown in housing activity, Treadway pointed out that mortgage interest rates have "suddenly increased dramatically" as a component in the cost of housing. While noting that thrift institutions are unable to meet current demand for home-ownership financing, Treadway also predicted that the housing finance demand will be filled "sooner or later."

The prospective house seller, he advised, should keep two points in mind:

Disposing of a house is not like selling a Treasury bond. Broker commissions, closing and related moving costs can add up to more than 10 percent of a typical sale. "Then one must consider the aggravation of moving out and possibly, when prices have dropped and the times are again favorable for home buying, of moving again."

If a crash comes and interest rates decline, there will be a sharp rise in unemployment. Otherwise, lower mortgage rates will revive potential housing demand, and "house prices will bounce back up again."

Treadway also said renting may be "preferable for lower tax-bracket households," because landlords will gain more from tax deductions of mortgage interest on units in growth areas not subject to rent-control laws. Thus, ownerships of rental property "may turn out to be profitable investments in the next few years."

Finally, Treadway said that "given the current small increase in house prices and the problems in housing finance," the next year may be the "best time" to purchase a house for those who can arrange financing. He argued that those with the ability to buy have a bargaining advantage in this depressed housing market.

"The key in arranging financing," he said, "will be to make sure that the mortgage loan can be easily refinanced at lower rates if there is a significant future decline in interest rates. In this respect, either an ARM [adjustable rate] mortgage or a fixed-rate mortgage withou an onerous repayment penalty could be a good bet."

But Treadway contended that fixed-rate mortgages will continue to be expensive and difficult to obtain because "easy capital gains at lenders' expense are going to be harder to come by even if inflation rises. And perhaps that is not such a bad thing."

His audience could forgive Treadway for that last plaintive opinion. You see, he works for Fannie Mae, which is now suffering losses due to its holding too many mortgages with drastic below-market yields.

Many older, lower-rate mortgages have been perpetuated long beyond their original life expectancy by second purchasers and by owners deciding to stay put with 7 percent or 8 percent mortgages rather than sell and move into a house with a new mortgage, on which the interest rate may not be fixed (unless it is FHA or VA, currently at 15 1/2 percent).