32 pages. "401(k) plan participants investing in mutual funds tend to hold lower-cost funds.... The expense ratios that 401(k) plan participants incur for investing in mutual funds have declined substantially since 2000.... The downward trend in the expense ratios that 401(k) plan participants incur for investing in mutual funds continued in 2014.... 401(k) plans are a complex employee benefit to maintain and administer, and they are subject to an array of rules and regulations.... Employers and employees generally share the costs of operating 401(k) plans."