Federal Reserve Chairman Ben S. Bernanke indicated that the central bank is weighing the potential costs from its $85 billion in monthly purchases of bonds while saying the unorthodox easing bolsters the economy.

“So far, we think we are getting some effect, it is kind of early,” Bernanke said Monday at the University of Michigan’s Gerald R. Ford School of Public Policy in Ann Arbor. “We are going to continue to assess how effective” the program is “because it is possible that as you move through time and the situation changes that the impact of these tools could vary.”