Congress has punted on doing the kind of scrutiny of federal agencies that’s required to prevent waste and keep the government running smoothly, according to a new report by Sen. Tom Coburn, an Oklahoma Republican who serves as the institution’s unofficial watchdog.

Mr. Coburn said the drop in oversight comes even as Congress is contemplating significant cuts to the Government Accountability Office, which is the investigative arm of Congress and is the one agency that’s kept up its pace of scrutiny.

“Long-term trends show a sharp decline in congressional oversight,” Mr Coburn said. “The problem, however, has not been a lack of funds to get it done. Over the last decade, the House and Senate budgets have nearly doubled in size and increased to a level that is more than $1 billion higher.”

But, he added, “despite this growth, everything from hearings to amendments to votes is decreasing, and with it oversight is in decline.”

His report found that Congress held 318 fewer hearings during the last two-year period, from 2009-2010, than it did in the previous Congress. The drop was powered by a marked decline in the House, where even the critical Oversight and Government Reform Committee held 59 fewer hearings than the previous Congress...