Guilherme Freitas

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I am a PhD Candidate in Economics at the California Institute of Technology. You can find my contact information and much more in my CV. I'm interested in a range of theoretical and applied problems in mechanism/market design, education, environmental economics and microeconomics in general. You might want to check out my research or my teaching resources and links.

Research

Monitoring Costs and the Management of Common-Pool-Resources (Job Market Paper)

Abstract. We lay down a model of a fishery and analyze the outcomes of a program of individual tradable quotas (ITQs) when quota enforcement is costly and imperfect. In this setting, decisions about enforcement level should not be dissociated from other design decisions --- like the total quota available or its initial distribution. To support those design decisions, we provide an extensive analysis of ITQ equilibria and full comparative statics for steady-state equilibria. To the best of our knowledge, this is the first time this analysis is carried out.

We also provide an extension of the full-compliance result that states that an ITQ program leads to an efficient use of the fish stock. Relaxing the assumption of full compliance, we present a principal-agent model where the principal is a fishery owner and the agents are the fishermen. The principal chooses how to allocate quota among the fishermen and how much to invest in monitoring to set the enforcement level. Agents choose how much fish to catch in face of their quota and the enforcement level. We show that, while the first-best outcome is not incentive-compatible, second-best outcomes can be implemented by an ITQ program if, and generically only if the expected violation fines depend on catch and quota only through absolute violations.

Finally, we establish sufficient conditions for fishermen's preferences over small changes in enforcement to be single-peaked. We emphasize that even though the distribution of quota endowments does not affect the attained ITQ equilibrium directly, it may affect outcomes indirectly if fishermen can influence the process that sets the cap or enforcement levels --- with or without quota trading. PDF.

Combinatorial Assignment Under Dichotomous Preferences (Working Paper)
Abstract. We consider the problem of assigning shares of a imperfectly divisible resource when preferences are dichotomous. One such problem is the problem of assigning bundles from a finite set of indivisible objects to a finite set of agents. When preferences are dichotomous, mech- anisms that satisfy voluntary participation only require agents to report a set of acceptable bundles/shares. We characterize strategyproof mechanisms for such problems and provide a mechanism that is utilitarian-efficient, strategyproof and envy-free, thereby showing that impossibilities like the ones pointed out by Kojima (2009) can be circumvented if we assume dichotomous preferences. We also show that, unlike in the assignment problem with dichoto- mous preferences of Bogomolnaia and Moulin (2004), the existence of a Lorenz-dominant assignment is not guaranteed. We analyze real-world difficulties involved in using efficient mechanisms, both from a computational and a strategic point of view. In particular, we show that utilitarian-efficient mechanisms require computations that can have running times that are exponentially long in the number of agents, but we point out that some classes of problems can be solved faster. We also show that agents with general preferences facing a mechanism that is strategyproof and efficient in the dichotomous domain might have an incentive to mis- report their acceptable shares/bundles, and in that case, the only profitable deviation is to report a smaller set of acceptable shares/bundles. PDF.

Vessel Buyback Auctions (with John O. Ledyard, in progress)

Voting with Common Values in Committees (with Matias Iaryczower and Matt Shum, in progress)

Teaching

I have taught the Mathcamp at the Division of the Humanities and Social Sciences at Caltech. The course reviews some of the most useful mathematical tools for the first-year PhD students at the division. Check the Syllabus, some code for computational sessions in the lab, and, most important, the problem set.

As the TA for an undergraduate course in Power Systems at Caltech, I wrote some quick notes on the basics of convex optimization and Karush-Kuhn-Tucker conditions. They are not very polished, but they are a good complement to more rigorous texts (mentioned in the final section), providing intuition and some useful hints.

I have worked as a volunteer tutor for School On Wheels, an NGO that provides one-one-one tutoring assistance for homeless children. If you believe that education is the way to provide opportunity to everyone, check them out! You can help in many ways: tutoring and donating are just two out of many options. For example, besides my tutoring activity, I also participated on a workshop where we discussed different issues in the education of homeless children. I talked about how to enrich the solution of math problems with an inquisitive trial-and-error approach. Here are the slides of the talk. And if you are teaching multiplication, it doesn't hurt to use a pretty multiplication table.

I am always happy to discuss ideas for improving education at all levels. A sample of topics on education that have recently caught my attention are: evaluation methods that give good feedback to our students and encourage learning; ways of using measurements, experiments and computation to aid middle and high-school students' understanding of mathematical concepts; and a curriculum for economics majors in college.