First, he said, “The committee’s microscope just isn’t accurate enough for us to pinpoint the actual date of a peak or a trough in the business cycle.” The committee only narrows things down to months. “That’s as precise as we’re comfortable with,” he said.

The closest the N.B.E.R. can come to specifying the end of the last recession is somewhere in June 2009. That imprecision itself is why, even if we were so inclined, we could not mark our calendars for an anniversary party on any specific day.

Then there’s another problem. The N.B.E.R. neither forecasts the future nor reports immediately on the past, he said. “We don’t even attempt to do forecasting,” he said. “We just try to measure what’s already happened. We go as fast as we can. But we take enough time to make sure that we’re right, sometimes a very long time. We’re proud of that.”

For example, the N.B.E.R. didn’t declare that the last recession was underway until December 2008, a year after the economy started to decline. “People made fun of us for that at the time,” Professor Hall said.

Similarly, it wasn’t until September 2010 that the committee was confident enough to declare June 2009 the end of the recession.

Professor Hall explained how the committee operates. The 10 eminent academics on the panel typically meet via conference call when they have something to decide, but Professor Hall said he hadn’t called a meeting “for a very long time.” Between sessions, he said, the members exchange spreadsheets with economic data but haven’t done so “for quite a while now.”

That inactivity suggested to me that the committee doesn’t think a recession is underway or likely to start soon. I asked whether he would confirm that.