 The big catalyst here is called automatic enrollment. So if you start working somewhere that provides a 401k, for example, and you don't get around to signing up for it, your employer will just do it for you. And a recent federal law is actually about to make that mandatory. This, in turn, has led to the highest participation rates. So the average plan participation rate is now 85 percent. Jeff Clark is head of defined contribution research at Vanguard. He authored the report.