Bookkeepers and purchasing agents at two of the federal governments' biggest agencies - the Pentagon and Agricultural Department - are disturbingly lax about keeping track of taxpayers' money.

A new audit shows that purchasing agents at the Pentagon are overpaying contractors millions of dollars a year because they fail to apply official cost-control rules. And a recent congressional study says the Department of Agriculture can't properly account for $1.6 billion of commodity certificates.The money overpaid to Pentagon contractors is usually recovered when the contracts are completed, but the interest that is supposed to be charged in such cases is usually not collected. This amounts to letting contractors use federal money at no cost, sort of interest-free loans.

The problem could be solved by simply following existing rules. Those rules require contractors to submit quarterly statements and quickly settle any overpayments.

The commodity certificates pose a bigger problem. Such certificates, which have a specific dollar value, are issued to farmers as partial government subsidy payments. They can be redeemed for cash, used to buy government-owned commodities, repay crop price support loans, or resold to other individuals.

Yet a General Accounting Office report showed that in some instances there are no records of issuance of certificates that have been reported as redeemed. Other certificates have been redeemed at a higher value than issued. And $1.6 billion worth simply cannot be accounted for.

That represents a huge potential for fraud and abuse. It also amounts to a huge claim on U.S. assets, either cash or government-owned farm supplies. That could have a major impact in a tight market because of a drought, for example.

The money involved in these scandals eventually comes out of the taxpayers' pockets, and the handling of those funds ought to be treated as a sacred trust. Clearly, too many federal bureaucrats don't feel that way.