If you've been saving to accumulate a down payment to buy a house, then you've probably been putting it somewhere other than the old cookie jar.

Money saved to buy houses often goes into savings and loan association that are potential sources of mortgages or into commercial banks or credit unions, all of which pay interest.

But as inflation continues and the competition among financial offerings stiffens, passbook savers are being distracted. It's not surprising that the thrift institutions -- which are already offering high-interest certificates to those with $10,000 to commit for six months -- want to come up with new incentives to attract depositors, especially for those planning to buy houses.

Some of the public policy initiatives used to abet savings and home ownership in other countries have been studied for the U.S. League of Savings Associations by Dr. Carroll R. Melton. He was in town this week to talk about the ways long-term saving by potential home buyers is being encouraged.

In his study of home ownership and saving in 31 countries, Melton found:

Some of Great Britain's building associations (comparable to the S&Ls in this country) offer a contract savings plan. The depositor agrees to save regularly an amount from 1 found to 20 found a month. At the end of five years, the government gives a bonus equal to 14 months of savings. If the funds are kept on deposit another two years, the bonus is doubled. Most important, the saver does not have to pay taxes on any of the interest.

In West Germany, the effective interest earned by the potential home buyer is 21 percent annually. Of course, borrowing rates also are higher.

In Israel, the savings account is indexed to offset inflation. The government adds enough money to a home buyer's account to offset any increase in prices -- beginning in the fourth year of saving.

In New Zealand, special building societies offer lotteries in which the winners get interest-free home loans. "Each month a ballot for loans is held.The winner is entitled to an interest-free loan of $2,000 New Zealand dollars for each 50-cent share held. The cash payment is entirely tax free," Melton said.

However, despite the incentives used in other nations, Melton cites statistics from the world housing survey of the United Nations showing that 63 percent of all U.S. dwellings are owner-occupied. That's the leading figure among 10 industrialized nations. The figure is 60 percent in Canada, 56 percent in Belgium, 44 percent in France and 28 percent in Switzerland.

Surprisingly, the same source shows that among 10 developing countries, Iraq has 83 percent owner-occupied dwellings; the Philippines, 79 percent, and Portugal the lowest at 44 percent.

In his report, Melton writes that "the most popular form of indirect incentive for home ownership is some type of special tax concession, the ultimate impact of which is to lower the cost of the house for the individual buyer. Tax concessions can act as catalysts on both the demand and supply sides of the housing market since they can be made available to buyers and lenders alike."

Suggestions for favored treatment for savers contemplating home purchases are not new in this country. Outgoing Sen. Edward Brooke (R-Mass.) earlier proposed a tax break on interest earned by persons who pledged to buy houses. The proposal died in committee. One reason was that the Treasury Department takes a dim view of any potential loss of tax revenue.

But last year the Congress gave major breaks on capital gain taxes, even to permit a one-time $100,000 exemption on capital gains obtained by persons over 55 on houses owned and resold at profits over the years. This was regarded as a major victory for home owners but a costly loss of Treasury receipts.

The National Association of Home Builders, which often rails against high mortgage interest rates, supports incentives for savings as both a potential for more home mortgages and also as a means to fight inflation and provide more investment capital.

"We'd like to see the potential first-time home buyer get a tax exemption on interest earned on a certain basic amount of savings," said David E. Stahl, executive vice president of the 113,000-member trade association.

The U.S. League of Savings Associations has announced that it plans to present copies of its housing finance and home ownership study to housing finance specialists on the Hill and in the administration.

John W. Stadtler, chairman of National Permanent Savings and Loan here, said that his recent travels as president of the International Union of Building Societies and Savings Associations had convinced him that other nations are providing "interesting incentives" for savings to provide mortgage loans.

Stadtler also conceded that the savings inflows have declined for many S&Ls in the U.S. and that the Congress might well consider encouraging more capital formation, as the Carter administration has urged to combat inflation.