As of December, the U.S. economy has expanded for a record 126 straight months, the longest time period in the country’s history according to the National Bureau of Economic Research. Put another way, the U.S. has avoided a recession for an entire calendar decade for the first time ever. CNBC reports:

“It is unusual that this has been such a persistent recovery,” Michelle Meyer, chief U.S. economist at Bank of America Merrill Lynch, told CNBC.

Economists cite a few reasons for why the expansion has lasted for so long. For one, the U.S. was coming from a low point at the end of the last decade. Much of the expansion over the past ten years has been spent recovering from the Great Recession…

Overall, economic expansions have started to last longer in the post-war period. The NBER, which keeps the official tally of recessions in the U.S., found expansions have lasted an average of 58.4 months from 1945 to 2009, compared to 35 months from 1919 to 1945. One reason for this, economists say, is that policymakers have gotten better at responding to changes in the economy while inflation has remained subdued…

Another reason economists say the expansion has lasted so long is that the memory of the crisis is still fresh in the minds of consumers and businesses, making them more risk-averse and alert to the next downturn.