He is especially known for developing the most widely used computational algorithm for calculating macroeconomic equilibrium under rational expectations in economies with heterogeneous agents and aggregate uncertainty when financial markets are incomplete.
"Long-Run Implications of Investment-Specific Technological Progress",JSTOR 2951349 American Economic Review, June 1997, (with Jeremy Greenwood and Zvi Hercowitz).
Casual empiricism suggests that technological progress is often embodied in the form of new and improved capital goods.
The results suggest that investment-specific technological progress accounts for the major part of U.S. economic growth over the postwar period.
"The Role of Investment-Specific Technological Change in the Business Cycle",doi:10.1016/S0014-2921(98)00058-0 European Economic Review, 2000, (with Jeremy Greenwood and Zvi Hercowitz).