For the past two decades, the federal government has piled up liabilities for taxpayers at a faster rate than their incomes have grown.

On top of current taxes, which can eat up 25 percent to 50 percent of a person's income, we now have contingent tax liabilities in the form of federal guarantees that are larger than our incomes. If we add the federal debt, the government has obligations and potential obligations that are about twice the size of the gross national product.Most taxpayers did not realize that they were liable for the deposits of insured savings and loan associations. They found out about their exposure only when the $500 billion bill came due.

Likewise, taxpayers do not realize that they are liable for federal guarantees of World Bank loans to impoverished Third World countries, a variety of Export-Import bank loans, federal guarantees of underfunded private pension plans, insured commercial bank deposits, student loans, small business loans, FHA and VA mortgage loans, guaranteed mortgage securities known as Fannie Mae and Freddie Mac, the Farm Credit System and debts of other government-sponsored entities blessed by the politicians with subsidized borrowing costs.

The subsidies, of course, encourage more of the guaranteed debts and thus balloon the taxpayers' liability.

As of 1990 federal guarantees of deposits, pensions and loans totaled $6.2 trillion, about $800 billion greater than the GNP.

Unless there is a major depression, most of the government's guarantees will not be faced with default. To the extent that defaults occur, the government of-ten holds collateral to offset part of the cost. Nevertheless, the obligations have grown so large that the S&L fiasco has forced the government to be more realistic about the future bills that may be presented to the taxpayers.

The government expects $225 billion to $350 billion in additional losses over the next five years.

Unless Congress restrains its spending, the budget deficit will reach new rec-ord highs.

Moreover, the government believes that banks and S&Ls, which have $2.8 trillion (about half the size of the GNP) in taxpayer-guaranteed deposits, may be going the way of the dinosaur. The banks' role as lenders of deposited funds is being undermined by the practice of packaging large numbers of individual loans into a security that is sold to investors. This already has happened to mortgage loans, and the government believes that business loans and consumer credit will also be packaged as securities. That would take the core business away from banks and threaten many with failure.

There may be more surprises than the government knows. Recently federal regulators forced commercial banks to write off 70 percent of their loans to Argentina and 40 percent of their loans to Brazil. Meanwhile, the World Bank continues to carry its loans to Argentina and Brazil on its books at full value.

Considering the enormous debts that the U.S. government has so recklessly assumed, it is shortsighted for Congress to neglect economic growth and to focus on income redistribution. The government's liabilities are far too large to be met with taxes. Only a growing economy can keep default at bay.