Declining fertility, mortality, and productivity rates in developed countries and the popularity of the social security privatization in Chile as a pathway to financial development have sparked a global interest in social security reform. This paper analyzes the effect of social security on saving using a panel of countries over 25 years. Variation in the characteristics of social security systems is used to determine whether less reliance on a pay-as-you-go, unfunded system is associated with higher national saving. There is little evidence that countries that implement defined-contribution reforms have higher trends in saving rates after the reform. Cross-sectionally, countries with pay-as-you-go systems tend to have lower saving rates, and this effect increases with the coverage rate on the system.

We estimate how much of the wealth of a sample of respondents to the Panel Study of Income Dynamics is held because some households face more income uncertainty than others. We begin by solving a theoretical model of saving, which we use to develop appropriate measures of uncertainty. We then regress households' wealth on our measures of uncertainty, and find substantial evidence that households engage in precautionary saving. Finally, we simulate the wealth distribution that our empirical results imply would prevail if all households had the same uncertainty as the lowest uncertainty group. We find that between 32 and 50% of wealth in our sample is attributable to the extra uncertainty that some consumers face compared to the lowest uncertainty group.