Thesis: Ph. D., Massachusetts Institute of Technology, Department of Economics, 2017. / Cataloged from PDF version of thesis. / Includes bibliographical references. / This thesis consists of three chapters on information transmission and utilization in marketplaces and their implications on firm competition and quality discovery. The first chapter analyzes the dynamic effect of sponsored search advertising on quality discovery on the Taobao.com retail platform. In a stylized model, a new product's boosted exposure from sponsored search ads could help the platform to infer how well the product converts exposure to sales (the quality measure) and award top organic search ranks accordingly. Hence, sellers with higher private quality signals would bid more aggressively for sponsored ads, which accelerates the platform's discovery of these high-quality products. An empirical analysis echoes the stylized model and reveal a synergy between the platform's PC and mobile interfaces. The second chapter (co-authored with Sara Fisher Ellison and Christopher M Snyder) studies price dynamics for computer components sold on a price-comparison website. We estimate a dynamic model of competition, backing out structural estimates of managerial frictions. The estimated frictions are substantial, concentrated in the act of monitoring market conditions rather than entering a new price. Coupled with supporting reduced-form statistical evidence, our analysis provides a window into the process of managerial price setting and the microfoundation of pricing inertia, issues of growing interest in industrial organization and macroeconomics. The third chapter analyzes the revelation of hard information in a buyer-seller relationship. The seller can choose whether and when to credibly reveal quality information and some buyers, called prosumers, have greater taste for quality than others. This paper first analyzes an alternating bargaining game allowing endogenous delay between communications in the fashion of Admati and Perry(1987), and constructs an equilibrium with delayed revelation of quality. The paper then analyzes an informed principal problem and found that under certain conditions, both seller types choose the same truth-telling mechanism that maximizes the revenue of the seller type with high quality. In both games, a high quality seller hides his quality information before the buyer acts in order to extract surplus from prosumers. / by Hongkai Zhang. / 1. Accelerated Quality Discovery through Sponsored Search Advertising in Online Marketplaces -- 2. Costs of Managerial Attention and Activity as a Source of Sticky Prices: Structural Estimates from an Online Market -- 3. Keeping Good Quality as a Surprise. / Ph. D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 1993. / Includes bibliographical references. / by Brigitte Condie Madrian. / Ph.D.

Massachusetts Institute of Technology. Dept. of Economics. Thesis. 1969. Ph.D. / Vita. / Includes bibliographies. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 1989. / Includes bibliographical references. / by Mohamad Lutfi Hammour. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references. / I addressed three questions in Labor Economics, using experimental and quasi-experimental variation to determine causality. In the first chapter, I ask whether playing longer in the NFL increases mortality in retirement. I compared players with very short careers with those with long careers. I also examined mortality for replacement players used briefly during the 1987 players' strike. I find that mortality is 15 percent higher for players with longer careers. This difference is even larger for positions with a high risk of injury. In the second chapter, we use a randomized experiment to evaluate the effects of academic achievement awards for first- and second-year college students studying at a Canadian commuter college. The award scheme offered linear cash incentives for course grades above 70. Awards were paid every term. Program participants also had access to peer advising by upperclassmen. Program engagement appears to have been high but overall treatment effects were small. The intervention increased the number of courses graded above 70 and points earned above 70 for second-year students, but generated no significant effect on overall GPA. Results are somewhat stronger for a subsample that correctly reproduced the program rules. In the third chapter, we examine two questions: (1) What is the value of receiving the first draft pick in the National Basketball Association?, and (2) Do teams lose intentionally to secure higher draft positions? We answer the first question by adjusting for the probability of winning the lottery using a propensity score methodology. The estimates indicate that winning the draft lottery increases attendance by 6 percentage points during the five-year period following the draft. Receiving the first pick is also associated with a small increase in win percentage. To answer the second question, we use a fixed-effects methodology that compares games in which a team can potentially change its lottery odds to games at the end of the season in which these odds are fixed. Since 1968, playoff-eliminated teams have seen around a 5 percentage point increase in win percentage once their lottery odds are fixed. This difference has ballooned above 10 percentage points in more recent years. / by Tyler Williams. / Ph.D.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Economics, 2014. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 147-150). / The first chapter takes advantage of the evolution of the regulatory and pricing environment in the first years of a large federal prescription drug insurance program for seniors - Medicare Part D - to explore interactions among adverse selection, switching costs, and regulation. I document evidence of both adverse selection of beneficiaries across contracts and switching costs for beneficiaries in changing contracts within Medicare Part D. Using an empirical model of contract choice and contract pricing, I show that in the present environment, on net, switching costs help sustain an adversely-selected equilibrium with large differences in risks between more and less generous contracts. I then simulate how switching costs may alter the impact of "filling" the Part D donut hole as implemented under the Affordable Care Act. I find that absent any switching costs, this regulation would have eliminated the differences in risks across contracts; however, in the presence of the switching costs that I estimate, the effect of the policy is largely muted. The second chapter (co-authored with Francesco Decarolis and Stephen Ryan) explores federal subsidy policies in Medicare Part D. We estimate an econometric model of supply and demand that incorporates the regulatory pricing distortions in the insurers' objective functions. Using the model, we conduct counterfactual analyses of what the premiums and allocations would be in this market under different ways of providing the subsidies to consumers. We show that some of the supply-side regulatory mechanisms, such as the tying of premiums and subsidies to the realization of average "bids" by insurers in a region, prove to be welfare-decreasing empirically. The third chapter studies two competing systems that comprise the German health insurance landscape. The two systems differ in the ability of insurers to underwrite individual-specific risk. In contrast to the community rating of the statutory insurance system, enrollees of the private plans face full underwriting and may be rejected by the insurers. I empirically assess to what extent the selection of "good risks" dominates the interaction between the two systems, using a regression discontinuity design based on statutory insurance enrollment mandates. I do not find compelling evidence of cream-skimming by private insurers from the statutory system. Motivated by this finding, I quantify the change in consumer welfare that would result if the government relaxed the statutory insurance mandate to lower income levels. / by Maria A. Polyakova. / Ph. D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 1994. / Includes bibliographical references. / by Shan Li. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Economics, 2005. / "June 2005." / Includes bibliographical references. / This thesis is a collection of three essays on exchange rate policies and international capital flows in emerging markets. The first chapter examines the theoretical foundations of the "fear of floating" that has been observed to characterize many emerging market exchange rate regimes. Building on a model that derives "fear of floating" from a desire to prevent non-fundamental shocks in foreign exchange markets affecting the real economy, the chapter shows that floating exchange rates can still be optimal in such an environment. It further argues that floating exchange rates should become more prevalent as emerging markets integrate more fully into the world economy. The second chapter investigates the empirical evidence on "fear of floating" with a view to determining whether the phenomenon is the optimal response of emerging markets to a volatile external environment, as supposed in the first chapter, or whether more emerging markets would optimally employ floating exchange rates. The chapter finds evidence that "fear of floating" has a dual aspect; that it might indeed be optimal during less severe external volatility, but during severe external shocks, fear of floating can lead to underinsurance against sudden stops in capital inflows. Such "fear of floating" is associated with a lack of credibility in monetary policymaking and the chapter argues that the evidence suggests that a credible commitment to floating exchange rates during severe external shocks would help insure emerging markets against sudden stops. The third chapter evaluates the link between foreign investment and corruption in emerging markets. / (cont.) A model is developed of the link between FDI and corruption and the model is evaluated with data from the World Bank's Business Environment and Enterprise Performance Survey. It is found that corruption reduces aggregate FDI flows, but also distorts the composition of FDI towards firms more willing to engage in certain forms of corruption. FDI does not necessarily import better standards of governance. The chapter concludes with policy recommendation -for addressing the corruption in emerging markets. / by Geraint Paul Jones. / Ph.D.

Thesis (Ph.D.) Massachusetts Institute of Technology. Dept. of Economics, 1946. / Appendix contains numerous pamphlets. Vita. / Bibliography: leaves 456-464. / by Finn Theodore Malm. / Ph.D.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Economics, 2018. / Cataloged from PDF version of thesis. / Includes bibliographical references. / This thesis consists of three chapters on inequality, interest rates and macroeconomic policies. The first chapter explores the macroeconomic consequences of the recent rise in permanent income inequality. First, I show that in many common macroeconomic models consumption is a linear function of permanent (labor) income. This implies that macroeconomic aggregates are neutral with respect to shifts in the distribution of permanent income. Motivated by this neutrality result, I develop novel approaches to test for linearity in U.S. household panel data. The estimates suggest an elasticity of 0.7, soundly rejecting linearity. I quantify the effects of this deviation from neutrality using a novel non-homothetic precautionary-savings model. In the model, the rise in U.S. permanent labor income inequality since the 1970s caused: (a) a decline in real interest rates of around 1%; (b) an increase in the wealth-to-GDP ratio of around 30%; (c) wealth inequality to rise almost as rapidly as it did in the data. The second chapter, joint with Sebastián Fanelli, develops a theory of foreign exchange interventions in a small open economy with limited capital mobility between home and foreign bond markets. Due to limited capital mobility, the central bank can implement nonzero bond spreads by managing its portfolio. Crucially, spreads are inherently costly as they allow foreign intermediaries to make carry-trade profits. Optimal interventions balance these costs with terms of trade benefits. We show that they lean against the wind of global capital flows to avoid excessive currency appreciation. Due to the convexity of the costs, interventions should be small and spread out, relying on credible promises (forward guidance) of future interventions. By contrast, excessive smoothing of the exchange rate path may create large spreads, inviting costly speculation. Finally, in a multi-country extension of our model, we find that the decentralized equilibrium features too much reserve accumulation and too low world interest rates, highlighting the importance of policy coordination. The third chapter, joint with Iván Werning, reconsiders the well-known Chamley-Judd result, according to which capital should not be taxed in the long run. For the main model in Judd (1985), we prove that the long run tax on capital is positive and significant, whenever the intertemporal elasticity of substitution is below one. The main model in Chamley (1986) imposes an upper bound on capital taxes. We provide conditions under which these constraints bind forever, implying positive long run taxes. When this is not the case, the long-run tax may be zero. However, if preferences are recursive and discounting is locally non-constant (e.g., not additively separable over time), a zero long-run capital tax limit must be accompanied by zero private wealth (zero tax base) or by zero labor taxes (first best). Finally, we explain why the equivalence of a positive capital tax with ever increasing consumption taxes does not provide a firm rationale against capital taxation. / by Ludwig Straub. / Ph. D.