Janssen's research focus is theoretical industrial economics. In particular, he conducts research on consumer search behavior and auctions, and has made several methodological contributions in the area of consumer search theory.[3][4] In addition, Janssen has launched a new subfield that studies the effects of consumer search in vertically structured industries.[5][6] In auction theory, Janssen studies the interaction between the way firms bid in auctions and the way they compete in markets after the auction. This is particularly important in spectrum auctions for mobile telecommunications.[7][8]
^Janssen, M. C. W., Parakhonyak & A. Parakhonyak, A. (2017). Non-reservation price equilibria and consumer search. Journal of Economic Theory,Volume 172, 120-162. https://doi.org/10.1016/j.jet.2017.08.003.
^Janssen, M. C. W., & Moraga-González, J. L. (2004). Strategic Pricing, Consumer Search and the Number of Firms. The Review of Economic Studies, 71(4), 1089–1118. https://doi.org/10.1111/0034-6527.00315
^Janssen, M., & Shelegia, S. (2015). Consumer Search and Double Marginalization. American Economic Review, 105(6), 1683–1710. https://doi.org/10.1257/aer.20121317
^Janssen, M., & Shelegia, S. (2020). Beliefs and Consumer Search in a Vertical Industry. Journal of the European Economic Association, 18(5), 2359–2393. https://doi.org/10.1093/jeea/jvz046
^Janssen, M. & Kasberger, B. (2019). On the Clock of the Combinatorial Clock Auction, Theoretical Economics (14), issue 4, p. 1271-1308.
^Bichler, M., Gretschko, V., & Janssen, M. (2017). Bargaining in spectrum auctions: A review of the German auction in 2015. Telecommunications Policy, 41(5), 325–340. https://doi.org/10.1016/j.telpol.2017.01.005