I don't know about mandatory, as 401(k)'s aren't mandatory in the first place. But incentivization using tax code would be sensible. You're absolutely right a

I don't know about mandatory, as 401(k)'s aren't mandatory in the first place. But incentivization using tax code would be sensible. You're absolutely right about pensions though; people pining for the days of the fixed benefit pension rarely are all that familiar with the pension plans that simply went bust due to inability to fund their liabilities due to market conditions. At least with a 401(k), you're not running out of money because your retirement is being invested too conservatively so as to pay someone older than you, leaving it empty by the time it's your turn.