Publications:
*NEW VERSION* Quality Versus Fit: Market Design and Externalities on Multidimensional Matching Platforms with Sam Flanders
PDF
Abstract: This paper studies externalities in one-to-one matching markets when agents have preferences over multidimensional types by utilizing a minimal search setting where agents are either high or low quality and have an idiosyncratic per- match “fit” shock. Applications include dating and marriage, job search, and school choice. It identifies a novel source of externalities that does not exist in the one-dimensional models focused on in the previous literature, but is endemic in multidimensional settings, appearing in both search and frictionless matching models so long as non-transferabilities are present. Agents match too aggressively on traits where preferences are homogeneous across agents (quality), and too little on traits where preferences are heterogeneous across agents (fit). This effect is decomposed into a intermatch externality – when you match to someone, you impose a cost on the rest of the market by removing them from it, and a intramatch externality – you don’t account for your partner’s payoffs when choosing partners. Given these generic externalities, we provide a survey of instruments a matching platform could use to improve surplus, analyzing for each the efficiency properties of the solution and its ease of implementation under a variety of assumptions. Having the platform act as a middle-man to make the transfers that agents cannot make directly is an obvious way to achieve first best, but may be difficult to implement. Utilizing two-part tariffs can improve efficiency somewhat, and is easy to implement, but cannot address the inefficient fit/quality tradeoff. Splitting the platform along quality can achieve first best in some settings, but will forego increasing returns to scale if they exist in the model. Censoring agents’ choice sets (curating the set of partners they can see on the platform) is only effective in some settings when studied in isolation, but when combined with two-part tariffs can achieve first best in any setting.
*NEW* Pricing and Incentives in Defined Contribution Retirement Systems with Sam Flanders & Marcela Parada-Contzen
PDF
Abstract: This paper studies the effects of different pricing schemes and auction mechanisms on overall surplus levels in a privately managed, defined contribution retirement system. One such system is in Chile, where retirement savings are mandatory and taken as a fixed percentage out of monthly salary. In Chile, a small number of banks compete on the prices they charge for managing a retirement account through bidding in a sealed-bid first-price auction. The winner of the auction gets monopoly rights over new consumers entering the labor market for two years. As with many other retirement systems, Chilean authorities have puzzled over the lower-than-expected level of retirement savings throughout the years. In this paper, we examine this problem by considering the effects of different pricing schemes on firm behavior. In particular, we develop a model that captures the strategic interactions between firms as well as demand characteristics to derive the pricing and bidding schemes that maximize efficiency. We consider a repeated auction with effort and compare three different pricing schemes -- the first is a fixed price that is paid regardless of the returns that a firm provides, the second is pricing based on returns whereby the firm can charge higher prices if they are able to get higher returns for their customers, and the third is a hybrid pricing scheme where firms bid on a guaranteed rate of return rather than taking a management fee as a fixed percentage of investment. We prove that the third pricing scheme is the most efficient.
Congestion, Gas Taxes, and Vehicle Choice with Sam Flanders
PDF
Abstract: Road congestion imposes large costs on individuals since long commutes yield significant decreases in productivity and leisure times. Congestion may also have ambiguous impacts on environmental pollution, either increasing it relative to a congestion-free regime through more frequent and longer vehicle usage, or decreasing it due to forgone travel. In this paper, we study the effects of gasoline tax policies on road congestion. To do this, we develop a model of household vehicle choice utilizing individual-level data from the 2009 National Household Travel Survey and combine it with a model of congestion, measured by average road speeds, which utilizes road-level data on traffic congestion collected by state and national-level departments of transportation. We estimate counterfactual regimes in which gas taxes are at different levels in order to answer questions regarding optimal gas taxes for a fixed geographical area.
- Team Teaching an Interdisciplinary First-Year Seminar on Magic, Religion, and the Origins of Science: A ‘Pieces-to-Picture’ Approach, Journal of the Scholarship of Teaching and Learning, Vol. 17, No. 1, February 2017, 24-36. Coauthored with Maia Dedrick and Shaily Patel
- Using Classroom Experiments To Teach Market Design and Matching Theory with Sam Flanders.
- A Model of Pricing on a Two-Sided Matching Platform with Horizontally Differentiated Agents
*NEW VERSION* Quality Versus Fit: Market Design and Externalities on Multidimensional Matching Platforms with Sam Flanders
Abstract: This paper studies externalities in one-to-one matching markets when agents have preferences over multidimensional types by utilizing a minimal search setting where agents are either high or low quality and have an idiosyncratic per- match “fit” shock. Applications include dating and marriage, job search, and school choice. It identifies a novel source of externalities that does not exist in the one-dimensional models focused on in the previous literature, but is endemic in multidimensional settings, appearing in both search and frictionless matching models so long as non-transferabilities are present. Agents match too aggressively on traits where preferences are homogeneous across agents (quality), and too little on traits where preferences are heterogeneous across agents (fit). This effect is decomposed into a intermatch externality – when you match to someone, you impose a cost on the rest of the market by removing them from it, and a intramatch externality – you don’t account for your partner’s payoffs when choosing partners. Given these generic externalities, we provide a survey of instruments a matching platform could use to improve surplus, analyzing for each the efficiency properties of the solution and its ease of implementation under a variety of assumptions. Having the platform act as a middle-man to make the transfers that agents cannot make directly is an obvious way to achieve first best, but may be difficult to implement. Utilizing two-part tariffs can improve efficiency somewhat, and is easy to implement, but cannot address the inefficient fit/quality tradeoff. Splitting the platform along quality can achieve first best in some settings, but will forego increasing returns to scale if they exist in the model. Censoring agents’ choice sets (curating the set of partners they can see on the platform) is only effective in some settings when studied in isolation, but when combined with two-part tariffs can achieve first best in any setting.
*NEW* Pricing and Incentives in Defined Contribution Retirement Systems with Sam Flanders & Marcela Parada-Contzen
Abstract: This paper studies the effects of different pricing schemes and auction mechanisms on overall surplus levels in a privately managed, defined contribution retirement system. One such system is in Chile, where retirement savings are mandatory and taken as a fixed percentage out of monthly salary. In Chile, a small number of banks compete on the prices they charge for managing a retirement account through bidding in a sealed-bid first-price auction. The winner of the auction gets monopoly rights over new consumers entering the labor market for two years. As with many other retirement systems, Chilean authorities have puzzled over the lower-than-expected level of retirement savings throughout the years. In this paper, we examine this problem by considering the effects of different pricing schemes on firm behavior. In particular, we develop a model that captures the strategic interactions between firms as well as demand characteristics to derive the pricing and bidding schemes that maximize efficiency. We consider a repeated auction with effort and compare three different pricing schemes -- the first is a fixed price that is paid regardless of the returns that a firm provides, the second is pricing based on returns whereby the firm can charge higher prices if they are able to get higher returns for their customers, and the third is a hybrid pricing scheme where firms bid on a guaranteed rate of return rather than taking a management fee as a fixed percentage of investment. We prove that the third pricing scheme is the most efficient.
Congestion, Gas Taxes, and Vehicle Choice with Sam Flanders
Abstract: Road congestion imposes large costs on individuals since long commutes yield significant decreases in productivity and leisure times. Congestion may also have ambiguous impacts on environmental pollution, either increasing it relative to a congestion-free regime through more frequent and longer vehicle usage, or decreasing it due to forgone travel. In this paper, we study the effects of gasoline tax policies on road congestion. To do this, we develop a model of household vehicle choice utilizing individual-level data from the 2009 National Household Travel Survey and combine it with a model of congestion, measured by average road speeds, which utilizes road-level data on traffic congestion collected by state and national-level departments of transportation. We estimate counterfactual regimes in which gas taxes are at different levels in order to answer questions regarding optimal gas taxes for a fixed geographical area.
