Accounting for private information

We study the quantitative properties of constrained efficient allocations in an environment where risk sharing is limited by the presence of private information. We consider a life cycle version of a standard Mirrlees economy where shocks to labor productivity have a component that is public information and one that is private information. The presence of private shocks has important implications for the age profiles of consumption and income. First, they introduce an endogenous dispersion of continuation utilities. As a result, consumption inequality rises with age even if the variance of the shocks does not. Second, they introduce an endogenous rise of the distortion on the marginal rate of substitution between consumption and leisure over the life cycle. This is because, as agents age, the ability to properly provide incentives for work must become less and less tied to promises of benefits (through either increased leisure or consumption) in future periods. Both of these features are also present in the data. We look at the data through the lens of our model and estimate the fraction of labor productivity that is private information. We find that for the model and data to be consistent, a large fraction of shocks to labor productivities must be private information.