Unless wealthy colleges start spending more of their endowment assets on student aid, they can expect more scrutiny from the federal government, a former Senate staff member said today.

Dean A. Zerbe, who recently resigned as senior counsel to Sen. Charles E. Grassley, said in an online discussion with The Chronicle of Philanthropy that members of Congress remain interested in discussing a mandatory payout requirement for college endowments that have more than $500-million in assets.

But whether lawmakers pursue legislation to enact such a change will “depend to a certain extent on the voluntary response by the colleges,” said Mr. Zerbe, who is now national managing director of Alliantgroup, a Houston-based tax-consulting company.

Senator Grassley, of Iowa, is the top Republican on the Senate Finance Committee. In January he and Montana Sen. Max Baucus, the committee’s top Democrat, sent letters to 136 wealthy colleges requesting information about their endowment spending, financial-aid policies, and tuition increases over the past decade.

Colleges have been responding to the committee’s request over the past few weeks. Some lobbyists expect the Finance Committee to hold a hearing on endowment spending practices this spring. —Brad Wolverton