The World Bank is much larger than its sister institution, the International Monetary Fund, with more than 5,000 employes in its Washington office. Professionals on the staff include economists, engineers, agronomists, nutrition experts, lawyers and financiers.

The president of the bank is typically an American, although his staff is recruited internationally. This year private banker A.W. (Tom) Clausen took over from Robert McNamara as the bank's head. So far Clausen has not been in the job long enough to make many changes, although some staff members expect him to reorganize in time.

The bank, which actually consists of three separate institutions, mostly lends money to developing countries for many individual projects such as building a dam or setting up a hospital or fertilizer plant. This is the main reason it has so many more staff members than the IMF, which just looks at broad economic policies of its member countries.

The bank has recently begun making "structural adjustment loans," which are to help governments pursue general economic policies rather than particular projects, but these still form only a very small part of the total lending.

The bulk of the bank's work involves lending at a profit money it has raised on the world's capital markets. It has a AAA rating on the bond markets, and no debtor government has ever defaulted. Its capital base is made up of the contributions from the richer of the 135 member countries, only a small part of which is callable capital.

In fiscal 1981, $8.8 billion was committed by the bank for "hard" loans of this sort. The projects are evaluated on their economic and social efficiency rather than just financial return. This enables the bank to lend for some development projects, such as education, which private finance is unwilling to back.

In addition, aid in the form of "soft" low-interest loans is given through the bank's International Development Association. Last year IDA committed $3.5 billion, although disbursements of the money were held up by the failure of the United States to authorize its share of the money until this summer.

The International Finance Corporation is also a part of the World Bank group. It concentrates on working with the private rather than government sector in recipient countries. It invested $811 million in fiscal 1981.

The total amount actually handed out by the Bank and IDA for "hard" and "soft" loans in fiscal 1981 was $6.9 billion, a 20 percent increase from fiscal 1980. Roughly half of this money went to agricultural and rural development projects, and more than a third went to the poorest countries in the world, those with per capita income of less than $371.