Commenting on these empirical studies in 2004 as a Federal Re-
serve Board governor two years prior to his appointment as chairman,
Ben Bernanke expressed support for more research to determine what
he called the “optimal long-run inflation rate,” or OLIR. While he
noted that the 2 percent figure may seem to be robust to a “variety of
assumptions about the costs of inflation, the structure of the economy,
the distribution of shocks, etc.,” he recommended more research to
clarify the range of uncertainty surrounding it. He also suggested more
research into a variety of details, including the specification of the infla-
tion index and the assumptions made about the long-run properties of
the models. He concluded that: