Sanghamitra Das

Indian Statistical Institute
7, S. J. S. Sansanwal Marg
New Delhi - 110016


NBER Working Papers and Publications

May 2010Back on the Rails: Competition and Productivity in State-owned Industry
with Kala Krishna, Sergey Lychagin, Rohini Somanathan: w15976
We use a proprietary data set on the floor-level operations at the Bhilai Rail and Structural Mill in India to understand the determinants of changes in plant productivity in 2000-2003. During this period there was a 35 percent increase in output with minimal changes in factors of production, but sizable reductions in production delays. We model interruptions to the production process and find that a large part of these reductions are attributable to training. Our results suggest that specific knowledge-enhancing investments can have very high returns, and that the threat of competition provides powerful incentives to undertake such investments.

Published: Sanghamitra Das & Kala Krishna & Sergey Lychagin & Rohini Somanathan, 2013. "Back on the Rails: Competition and Productivity in State-Owned Industry," American Economic Journal: Applied Economics, American Economic Association, vol. 5(1), pages 136-62, January. citation courtesy of

December 2001Market Entry Costs, Producer Heterogeneity, and Export Dynamics
with Mark J. Roberts, James R. Tybout: w8629
As the exchange rate, foreign demand, production costs and export promotion policies evolve, manufacturing firms are continually faced with two issues: Whether to be an exporter, and if so, how much to export. We develop a dynamic structural model of export supply that characterizes these two decisions and estimate the model using plant-level panel data on Colombian chemical producers. The model embodies uncertainty, plant-level heterogeneity in export profits, and sunk entry costs for plants breaking into foreign markets. Our estimates, and the simulation exercises that they support, yield several implications. First, entry costs are typically large, but vary greatly across producers. Second, there is substantial cross-plant heterogeneity in gross expected export profit streams. Third, th...

Published: Sanghamitra Das & Mark J. Roberts & James R. Tybout, 2007. "Market Entry Costs, Producer Heterogeneity, and Export Dynamics," Econometrica, Econometric Society, vol. 75(3), pages 837-873, 05. citation courtesy of

December 1990A Micro Econometric Model of Capital Utilization and Retirement
The paper presents a micro econometric model of capital utilization and retirement. Some estimates of a firm's discrete decision problem with regard to an existing piece of capital--whether to operate, hold idle or retire it--are obtained, in the context of the US cement industry, by solving a discrete choice stochastic dynamic programming model. The estimates are then used to simulate effects of product and input price changes, and changes in the size and age of capital on a firm's propensity to operate, hold idle and retire capital.

Published: Review of Economic Studies Volume 59, pp.277-297 April 1992

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