Macroeconomic Consequences of Alternative Reforms to the Health Insurance System in the U.S.

This paper examines the macroeconomic and welfare implications of alternative re- forms to the U.S. health insurance system. In particular, I study the effect of the expansion of Medicare to the entire population, the expansion of Medicaid, an individ- ual mandate, the removal of the tax break to purchase group insurance and providing a refundable tax credit for insurance purchases. To do so, I develop a stochastic OLG model with heterogenous agents facing uncertain health shocks. In this model individ- uals make optimal labor supply, health insurance, and medical usage decisions. Since buying insurance is endogenous, my model captures how the reforms may affect the characteristics of the insured as well as health insurance premiums. I use the Medi- cal Expenditure Panel Survey to calibrate the model and succeed in closely matching the current pattern of health expenditure and insurance demand as observed in the data. Numerical simulations indicate that reforming the health insurance system has a quantitatively relevant impact on the number of uninsured, hours worked, and welfare.Health insurance reform, Heterogeneous agent model, Welfare analysis

RNG in turbulence and modeling of bypass transition

Two projects are considered: the Renormalization Group (RNG) analysis of turbulence modeling, and the calculation of bypass transition through turbulence modeling. RNG is a process which eliminates small scales on the uneliminated large scales as the change in the transport properties. It is because of this property of RNG that it was previously suggested that RNG could be used as a model builder in turbulence modeling. The possibility is studied of constructing RNG based turbulence models, and to try to proceed to do the modeling through RNG in parallel with the classical approach. The numerical predictions made by RNG models and by classical models is compared against data from Direct Numerical Simulation. While in an environment with freestream turbulence, the transition initiated by the instability of the laminar boundary layer to Tollmien-Schlichting waves is found to be a bypass one in which turbulent spots are formed without T-S wave amplification. The formation is a random process, and flow within a turbulent spot is almost fully turbulent. This suggests the possibility of using turbulence modeling to describe and predict the bypass transition