TY  - JOUR
AU  - Schott,Peter K.
AU  - Bernard,Andrew B.
AU  - Redding,Stephen J.
TI  - Products and Productivity
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 11575
PY  - 2005
Y2  - August 2005
UR  - http://www.nber.org/papers/w11575
L1  - http://www.nber.org/papers/w11575.pdf
N1  - Author contact info:
Peter K. Schott
Yale School of Management
135 Prospect Street
New Haven, CT 06520-8200
Tel: 203/436-4260
Fax: 203/432-6974
E-Mail: peter.schott@yale.edu

Andrew B. Bernard
Tuck School of Business at Dartmouth
100 Tuck Hall
Hanover, NH  03755
Tel: 603/646-0302
Fax: 603/646-0995
E-Mail: Andrew.B.Bernard@dartmouth.edu

Stephen J. Redding
Department of Economics
and Woodrow Wilson School
Princeton University
Fisher Hall
Princeton, NJ 08544
Tel: 609/258-4016
Fax: 609/258-6419
E-Mail: reddings@princeton.edu
AB  - Firms' decisions about which goods to produce are often made at a more disaggregate level than the data observed by empirical researchers. When products differ according to production technique or the way in which they enter demand, this data aggregation problem introduces a bias into standard measures of firm productivity. We develop a theoretical model of heterogeneous firms endogenously self-selecting into heterogeneous products. We characterize the bias introduced by unobserved variation in product mix across firms, and the implications of this bias for identifying firm and industry responses to exogenous policy shocks such as deregulation. More generally, we demonstrate that product switching gives rise to a richer set of industry-level dynamics than models where firm product mix remains fixed.
ER  -