The share of firms aged 16 years or more was 23 percent in 1992, but leaped to 34 percent by 2011—an increase of 50 percent in two decades. The share of private-sector workers employed in these mature firms increased from 60 percent to 72 percent during the same period. Perhaps most startling, we find that employment and firm shares declined for every other firm age group during this period.
We explore three potential contributing factors driving the increasing share of economic activity occurring in older firms, and find that a secular decline in entrepreneurship is playing a major role. We also believe that increasing early-stage firm failure rates might be a growing factor.
From Ian Hathaway and Robert E. Litan, there is more here.