Beyond those issues are the questions of how and when savings get converted into retirement income. Some people will inefficiently choose to stop working when retirement funds become available. Others who would rationally stop working won't do so because of limited access to their accumulated funds. It isn't easy to adjust the tradeoffs. Moreover, a uniform retirement age also has some inefficiency.
Life expectancy can vary by sex, income, and education.
People with short life expectancies might be acting rationally if they choose lower savings and earlier retirement. Differences and policy choices can go well beyond the method of accumulation, however. For example, all plans need a mechanism to convert savings into flows of retirement income. Chileans have two options at retirement age, whether they stop working or not. One is to elect monthly withdrawals that are subject to a monthly maximum.