Gilchrist DS, Luca M, Malhotra D. When 3+1 > 4: Gift Structure and Reciprocity in the Field. Management Science. Forthcoming.Abstract

Do higher wages elicit reciprocity and lead to increased productivity? In a field experiment with 266 employees, we find that paying above-market wages, per se, does not have an effect on productivity relative to paying market wages (in a context with no future employment opportunities). However, structuring a portion of the wage as a clear and unexpected gift—by offering a raise (with no additional conditions) after the employee has accepted the contract–does lead to higher productivity for the duration of the job. Targeted gifts are more efficient than hiring more workers. However, the mechanism underlying our effect makes this unlikely to explain persistent above-market wages. 

Gilchrist DS. Patents as a Spur to Subsequent Innovation? Evidence from Pharmaceuticals. American Economic Journal: Applied Economics. 2016;8 (4) :189-221.Abstract

This paper examines how an incumbent's patent protection acts as an implicit subsidy toward non-infringing substitutes. I analyze whether classes of pharmaceuticals whose first entrant has a longer period of market exclusivity (time between approval and generic entry) see more subsequent entry. Instrumenting for exclusivity using plausibly exogenous delays in the development process, I find that a one-year increase in the first entrant's market exclusivity increases subsequent entry by 0.2 drugs. The effect is stronger for subsequent entrants that are lesser clinical advances, suggesting it is driven primarily by imitation.

Gilchrist DS, Sands EG. Something to Talk About: Social Spillovers in Movie Consumption. Journal of Political Economy. 2016;24 (105) :1339-1382.Abstract

We exploit the randomness of weather and the relationship between weather and movie-going to quantify social spillovers in movie consumption. Instrumenting for early viewership with plausibly exogenous weather shocks captured in LASSO-chosen instruments, we find that shocks to opening weekend viewership are doubled over the following five weekends. Our estimated momentum arises almost exclusively at the local level, and we find no evidence that it varies with either ex-post movie quality or the precision of ex-ante information about movie quality, suggesting the observed momentum is driven in part by a preference for shared experience, and not only by social learning.

Ashlagi I, Gilchrist DS, Roth AE, Rees MA. Nonsimultaneous Chains and Dominos in Kidney Paired Donation - Revisited. American Journal of Transplantation. 2011;11 (May) :984-994. Link
Ashlagi I, Gilchrist DS, Roth AE, Rees MA. NEAD chains in Transplantation. American Journal of Transplantation. 2011;11 (December) : 2780-2781. Link