Michael L. Katz

UC, Berkeley
Haas School of Business
545 Student Services #1900
Berkeley, CA 94720-1900

E-Mail: EmailAddress: hidden: you can email any NBER-related person as first underscore last at nber dot org
Institutional Affiliation: University of California at Berkeley

NBER Working Papers and Publications

November 2016Complementarity without Superadditivity
with Steven Berry, Philip Haile, Mark Israel: w22811
The distinction between complements, substitutes, and independent goods is important in many contexts. It is well known that when consumers’ conditional indirect utilities for two goods are superadditive, the goods are gross complements. Generalizing insights in Gans and King (2006) and Gentzkow (2007), we show that superadditivity between one pair of goods can also introduce complementarity between competing pairs of goods. One implication is that lower prices can result from a merger between producers of goods that themselves offer no superadditivity.

Published: Berry, Steven & Haile, Philip & Israel, Mark & Katz, Michael, 2017. "Complementarity without superadditivity," Economics Letters, Elsevier, vol. 151(C), pages 28-30. citation courtesy of

February 2016Net Neutrality, Pricing Instruments and Incentives
with Joshua S. Gans: w22040
We correct and extend the results of Gans (2015) regarding the effects of net neutrality regulation on equilibrium outcomes in settings where a content provider sells its services to consumers for a fee. We examine both pricing and investment effects. We extend the earlier paper’s result that weak forms of net neutrality are ineffective and also show that even a strong form of net neutrality may be ineffective. In addition, we demonstrate that, when strong net neutrality does affect the equilibrium outcome, it may harm efficiency by distorting both ISP and content provider investment and service-quality choices.
January 2005Merger Policy and Innovation: Must Enforcement Change to Account for Technological Change?
with Howard A. Shelanski
in Innovation Policy and the Economy, Volume 5, Adam B. Jaffe, Josh Lerner and Scott Stern, editors
August 2004Merger Policy and Innovation: Must Enforcement Change to Account for Technological Change?
with Howard A. Shelanski: w10710
Merger policy is the most active area of U.S. antitrust policy. It is now widely believed that merger policy must move beyond its traditional focus on static efficiency to account for innovation and address dynamic efficiency. Innovation can fundamentally affect merger analysis in two ways. First, innovation can dramatically affect the relationship between the pre-merger marketplace and what is likely to happen if a proposed merger is consummated. Thus, innovation can fundamentally influence the appropriate analysis for addressing traditional, static efficiency concerns. Second, innovation can itself be an important dimension of market performance that is potentially affected by a merger. We explore how merger policy is meeting the challenges posed by innovation.
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