Assistant Professor - Economics
London Business School
Regent's Park | London NW1 4SA | United Kingdom
Direct line +44 (0)20 7000 8471
I am a business economist. I use game theory
to answer questions in competition policy and strategy, covering topics such as
pricing, bargaining, and supply-chains.
Before joining LBS in 2008, I received a doctorate from the U. Lausanne. As part of my doctoral studies, I was awarded a MSc. in Quantitative Economics from U. Toulouse and I was a doctoral researcher at Columbia U for two years.
Research Interests: Microeconomics - Industrial Organization and Game Theory
“Downstream concentration and producer's capacity choice: why bake a larger pie when getting a smaller slice"
Rand Journal of Economics, winter 2007 Vol. 38 pp. 948-966
We study the effect of downstream horizontal mergers on the upstream producer's capacity choice. Contrary to conventional wisdom, we find a non-monotonic relationship: horizontal mergers induce a higher upstream capacity if the cost of capacity is low and a lower upstream capacity if this cost is high. We explain this result by decomposing the total effect into two competing effects: a change in hold-up and a change in bargaining erosion.
“Inefficient sales delays by a durable-good monopoly facing a finite number of buyers”
Rand Journal of Economics, fall 2013 Vol. 44 pp. 425-437
This article offers a new explanation for unscheduled price cuts and slow adoption of durable-goods. We study a standard durable-goods monopoly model with a finite number of buyers and show that this game can have multiple subgame perfect equilibria in addition to the Pacman outcome--including the Coase conjecture. Of particular interest is a class of equilibria where the seller first charges a high price, and only lowers that price once some---but not all---high-valuation buyers purchase. This price structure creates a war of attrition between those buyers, which delays market clearing and rationalizes unscheduled purchase and price cut dates.
Journal of Economic Theory, forthcoming
We study a model where a central player (the principal) bargains bilaterally with each of several players (the agents) to create and share the surplus of a coalitional game. It is known that if the payments agreed with the agents are rebargained in case any bilateral negotiation breaks down, then the Shapley value is the unique efficient and individual rational outcome consistent with bilateral Nash bargaining. Here we show that when the agreed payments cannot be rebargained, i.e., they are indissoluble, that outcome is also unique but coincides instead with the Nucleolus of an associated bankruptcy problem. We provide a strategic foundation for this outcome. Then we study how the ability to rebargain affects the principal’s payoff according to the properties of the surplus function. We find, for example, that indissoluble agreements hurt the principal when agents are complements and they benefit him when they are substitutes.
Previous version with additional applications, circulated as "The
worth of binding agreements in one-to-many bargaining."
invited resubmission to the Rand Journal of Economics
A monopolist producer, offering private contracts to competing retailers, may be unable to exercise its monopoly power because of the scope for opportunistic behavior. In this paper we show that the producer eliminates this problem using bilateral contracts with buybacks, together with a price ceiling if needed (buybacks are a price paid by the producer to the retailer for each unit of unsold stock). Contracts with buybacks alone can be sufficient to solve the problem if either the elasticity of demand (at the monopoly price) is not too small or the number of retailers is large.
Many manufacturers offer retailers the possibility to return unsold stocks for a fraction of the wholesale price. We show that when competing retailers do not observe each other’s stocks before choosing prices, returns intensify retail competition by squeezing retailers’ margins. This can increase significantly the manufacturer’s profit. There is however a trade-off: returns intensify retail competition by giving retailers the incentive to order excess stocks, the production cost of which is paid up-front by the manufacturer. Therefore the optimal return price, as a percentage of the wholesale price, decreases as the manufacturing marginal cost increases
"Large buyer discounts or premium?" (with Roman Inderst)
We study bilateral bargaining between buyers and sellers of substitute goods. A novel bargaining framework encompasses the outcome of auctions in truthful menus as limiting cases. Looking at the equilibrium per unit transaction prices, we find that a larger buyer pays higher per unit price when the bargaining power of buyers in bilateral negotiations is sufficiently low---and a lower price otherwise. We explain this result by decomposing the overall effect of a buyer's size into its components of "buyer dependency" and "seller dependency," and showing that each effect respectively increases the maximum and lowers the minimum per unit price paid by a larger buyer. The actual effect of size is therefore to increase the range of equilibrium prices. Thus buyer dependency on sellers is a force that counters and may overturn the buyer power often associated with size due to seller dependency. Similar results hold in the case of horizontal mergers by sellers.
"Unions and investment with intra-firm bargaining"