TY  - JOUR
AU  - Rotemberg,Julio J.
AU  - Woodford,Michael
TI  - Cyclical Markups:  Theories and Evidence
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 3534
PY  - 1990
Y2  - December 1990
UR  - http://www.nber.org/papers/w3534
L1  - http://www.nber.org/papers/w3534.pdf
N1  - Author contact info:
Julio J. Rotemberg
Graduate School of Business
Harvard University, Morgan Hall
Soldiers Field
Boston, MA  02163
Tel: 617/495-1015
Fax: 617/496-5994
E-Mail: jrotemberg@hbs.edu

Michael Woodford
Department of Economics
Columbia University
420 W. 118th Street
New York, NY 10027
Tel: 212/854-1094
Fax: 212-854-8059
E-Mail: mw2230@columbia.edu
AB  - If changes in aggregate demand were an important source of macroeconomic fluctuations, real wages would be countercyclical unless markups of price over marginal cost were themselves countercyclical. We thus examine three theories of markup variation at cyclical frequencies. The first assumes only that the elasticity of demand is a function of the level of output. In the second, firma face a tradeoff between exploiting their existing customers and attracting new customers. Markups then depend also on rates of return and future sales expectations; a high rate of return or expectations of low sales growth lead firms to assign a lower value to future revenues from new customers. Firma thus raise prices and markups. In the third theory, markups are chosen to ensure that no one deviates from an (implicitly) collusive understanding. Increases in rates of return or pessimistic expectations then lead firms to be less concerned with future punishments so that markups fall. Aggregate post-war data from the U.S. are moat consistent with the predictions of the implicit collusion model.
ER  -