My dissertation within macroeconomics puts special emphasis on uncovering the effects of market power within product and labor markets. I conduct these studies using novel empirical techniques and detailed granular data sets at the firm- and household-levels.In the first chapter, coauthored with Shruti Mishra, we consider how firms’ price-setting decisions are affected by the properties of their markup. We start by designing a general oligopoly framework that accounts for firm heterogeneity, firm granularity, and the effects of market share distribution. We use this structural model to decompose the effect of price on the quantity demanded into a direct price effect and an indirect effect coming from the impact of the market-level aggregates, such as market-level price. This decomposition allows us to take care of all the degrees of heterogeneity in a flexible manner. Under plausible assumptions, the most crucial of which we test in the data, all the information about the distribution of shares within the market will be accounted for by the variation of the market aggregates. Under these conditions, we can estimate the structural parameters that do not depend on the distribution of shares within the market. We use the model to inform our empirical strategy and apply it to the ACNielsen Retail Scanner Data. We test the assumptions put forward by the theory, estimate structural parameters and then use the decomposition formulas to calculate the elasticity of the firm’s demand and other parameters important for the markup variation. We find that elasticity depends sharply on the firm’s market share and decreases significantly as market shares increase. There is a positive dependence of demand elasticities on relative prices (superelasticity), in line with Marshall’s second law of demand. Additionally, elasticity depends on the levels of competitiveness within the market. Even if a firm’s market share stays the same, its elasticity decreases if the market becomes less competitive. Lastly, we apply our estimates to calculate the optimal pass-through of marginal costs into prices and strategic complementarity. We find that an individual firm’s pass-through is contained between zero and one, but depends sharply on the firm’s market share. We find that strategic complementarity between two firms depends on both of their shares and is not symmetric so the degree of strategic complementarity between a small and a large firm, between two small firms, between two large firms, or between large and small firms would all be different. We then assess the non-linear effects of the marginal cost shock on the price and find that pass-through depends positively on the size of the marginal cost shock. This means that the total effect of marginal cost shock on prices is non-linear and that firm prices are more responsive to marginal cost increases than to marginal cost decreases. For market leaders, the pass-through of a large negative marginal cost shock would be close to zero, while the pass-through of a large positive marginal cost shock would approach that of small firms. In the second chapter, coauthored with Rui Mano, Yannick Timmer, and Anke Weber, we study the effect of the firm granularity in the labor market on their hiring decisions. We argue that prevalence of firms controlling large vacancy shares plays an important role in the transmission of monetary policy to labor demand and wage growth and can partially explain the flattening of the wage Philips curve after the GFC. Accommodative monetary policy raises the marginal product of labor, incentivizing all firms to hire more. However, since the wage elasticity of labor demand is lower for high vacancy share firms, they can hire more workers without raising wages disproportionately. We study this effect in the Burning Glass Technology vacancy microdata and, consistently with this mechanism, show that accommodative monetary policy increases labor demand more for high vacancy share firms and that this comes without a disproportionate response in wages. In aggregate, this implies that due to the presence of firms controlling large vacancy shares, accommodative monetary policy can lead to a decline in the unemployment rate that is decoupled from an increase in wage growth. Quantitatively, a firm at the 50th percentile of vacancy share distribution increases its labor demand by ≈ 7% in response to a 10 basis point surprise monetary loosening while a firm at the 95th percentile of the vacancy share distribution increases labor demand by ≈ 9%. Moreover, the effect of monetary policy shocks on firms with high vacancy share is much more persistent, with effects economically large and statistically significant at least for eight quarters. At the same time, there is no comparable differential response of wages, so even though firms with high vacancy shares hire more, they don’t have to increase their wages by more. In this case, more hiring does not result in a comparable increase in wage inflation. This channel can partly explain the flattening of the wage Phillips curve and the “wage-less” recovery after the Global Financial Crisis.In the third and last chapter, coauthored with Shruti Mishra, we study the impact of wealth heterogeneity on labor supply decisions. In the standard model, the positive wealth effect should decrease the willingness to supply labor. In the macroeconomic setting, this means that the direction and the magnitude of the wealth effect will determine whether people search for jobs more actively after a monetary intervention. For example, if unemployed consumers are indebted, they experience a negative wealth effect after a monetary contraction, search for jobs more actively and increase their probability of finding a job, therefore, reducing the total unemployment response. The sign and magnitude of the overall effect of monetary policy on unemployment will therefore depend on whether unemployed consumers are indebted and the magnitude of their debt. To study this mechanism, we develop a theoretical framework with heterogeneous consumers and employment search efforts and then decompose the effect of the monetary policy shock on aggregate unemployment. We test the prediction of the model in both micro and aggregate data. To test the prediction of the model in the aggregate, we estimate the coefficient of the interaction term between the debt-to-income ratio and Romer and Romer monetary policy shock. For the microdata, we use a similar regression with unemployment and mortgage variables for individual consumers from the PSID panel dataset. Consistently with the proposed mechanism, we find that the intuitive negative effect on employment of the monetary contraction is virtually non-existent or even reversed for indebted consumers. The three chapters together paint a complex picture of the impact of market power on macroeconomic variables. First, product market power impacts price-setting decisions of the firms and affects the dynamic of prices and inflation, effectively leading less concentrated economies to behave as if they have more flexible prices. Second, firms that control large share of vacancies in their labor market conduct hiring differently from their smaller counterparts leading to more quantity expansion. Lastly, labor markets exhibit complex supply dynamics as well, with labor supply potentially intensifying during recessions, which might lead the bargaining power of firms to become countercyclical. All these effects hold first-order significance for macroeconomic dynamics and influence our ability to project the future or asses the effects of monetary policy.

This thesis studies four independent resource allocation problems with different assumptions on information available to the central planner, and strategic considerations of the agents present in the system. We start off with an online, non-strategic agents setting in Chapter 1, where we study the dynamic pricing and learning problem under the Bass demand model. The main objective in the field of dynamic pricing and learning is to study how a seller can maximize revenue by adjusting price over time based on sequentially realized demand. Unlike most existing literature on dynamic pricing and learning, where the price only affects the demand in the current period, under the Bass model, price also influences the future evolution of demand. Finding arevenue-maximizing dynamic pricing policy in this model is non-trivial even in the full information case, where model parameters are known. We consider the more challenging incomplete information problem where dynamic pricing is applied in conjunction with learning the unknown model parameters, with the objective of optimizing the cumulative revenues over a given selling horizon of length 𝑻. Our main contribution is an algorithm that satisfies a high probability regret guarantee of order 𝑚²/³; where the market size 𝑚 is known a priori. Moreover, we show that no algorithm can incur smaller order of loss by deriving a matching lower bound. We then switch our attention to a single round, strategic agents setting in Chapter 2, where we study a multi-resource allocation problem with heterogeneous demands and Leontief utilities. Leontief utility function captures the idea that for certain resource allocation settings, the utility of marginal increase in one resource depends on the availabilities of other resources. We generalize the existing literature on this model formulation to incorporate more constraints faced in real applications, which in turn requires new algorithm design and analysis techniques. The main contribution of this chapter is an allocation algorithm that satisfies Pareto optimality, envy-freenss, strategy-proofness, and a notion of sharing incentive. In Chapter 3, we study a single round, non-strategic agent setting, where the central planner tries to allocate a pool of items to a set of agents who each has to receive a prespecified fraction of all items. Additionally, we want to ensure fairness by controlling the amount of envy that agents have with the final allocations. We make the observation that this resource allocation setting can be formulated as an Optimal Transport problem, and that the solution structure displays a surprisingly simple structure. Using this insight, we are able to design an allocation algorithm that achieves the optimal trade-off between efficiency and envy. Finally, in Chapter 4 we study an online, strategic agent setting, where similar to the previous chapter, the central planner needs to allocate a pool of items to a set of agents who each has to receive a prespecified fraction of all items. Unlike in the previous chapter, the central planner has no a priori information on the distribution of items. Instead, the central planner needs to implicitly learn these distributions from the observed values in order to pick a good allocation policy. Additionally, an added challenge here is that the agents are strategic with incentives to misreport their valuations in order to receive better allocations. This sets our work apart both from the online auction mechanism design settings which typically assume known valuation distributions and/or involve payments, and from the online learning settings that do not consider strategic agents. To that end, our main contribution is an online learning based allocation mechanism that is approximately Bayesian incentive compatible, and when all agents are truthful, guarantees a sublinear regret for individual agents' utility compared to that under the optimal offline allocation policy.

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he assumption of a purely self-interested supervisor in a three-tier hierarchy (a principal-supervisor-agent framework) gives rise to the possibility of supervisor-agent collusion which lowers the principal's profits. It has also been shown that the transfer of information in side contract negotiations between the supervisor and the agent may hinder collusion and maintain high principal profits. In chapter 2, I show that imposing "credible" updating of type beliefs during negotiations can guarantee one of two outcomes that are Pareto superior for the supervisor-agent coalition. I further refine the equilibria by endogenizing the decision of who makes the side contract proposal, and a unique collusive equilibrium results. In allowing the principal to form a collusion-proof incentive contract, I find that the only plausible solution is for the principal to ignore the supervisor. It is clear that there is no value at all to the principal in hiring a self-interested supervisor. This casts doubt on the validity of the assumption that the supervisor is self-interested, and I discuss some possible alternatives. Chapter 3 studies job matching inefficiencies under two-sided uncertainty. I examine these inefficiencies in a setting of a single-stage, simultaneous-offer bargaining situation, where the applicant does not know his productivity with the firm, and the employer does not know the applicant's reservation wage. I compare linear bid strategy equilibria between the cases where the applicant is uninformed of his productivity and where he is informed. I find that the payoff to the applicant is higher if he is informed. He is thus willing to collude with an informed person within the firm, paying him up to the difference in payoffs to obtain his productivity information. It is noteworthy that the collusive equilibrium is always more efficient than the non-collusive equilibrium, and that most types of employer prefer the applicant to have the knowledge. In the cases that the employer does not wish the applicant to possess the information, I examine possible reward schemes for the employer to use to deter collusion. I find, however, that a successful reward scheme is too costly to the employer, and coalition formation always occurs in equilibrium. Chapter 4 studies the strategic choice of job tenures to maximize lifetime earnings. A worker's salary typically increases with tenure, and the possible net starting salary at a new job depends on such factors as search costs, training period duration, rate of human capital accumulation, and experience. The worker thus wishes to choose appropriate tenures considering the levels of these factors for the industry in which he works. I set up a general framework for the problem, and solve using specific functional forms for salary increments and the new starting salary. I find that these factors are important in determining the optimal number of jobs to work, and the optimal distribution of tenures among the jobs. It is easy to see how variations in these factors across industries can help explain variations in turnover rates and tenure choices of individuals at different points in their working lifetimes. Also, we see how realistic variations in these values over the course of a worker's lifetime yield results consistent with empirical findings. / Ph. D.

Mehra and Prescott's (1985) equity premium puzzle has stirred continued debate on just why the average return on equity has been so high relative to the risk-free rate. Recent work by Backus, Gregory, and Zin (1989), Knez and Snow (1992), and Trainor (1992) have also documented a liquidity premium puzzle. In addition, Fama and French (1992) have found that beta has no explanatory power in explaining an asset's excess return. These studies point out that current financial models are unable to explain even the most basic premise that assets with greater risk have higher returns. The question that now arises is why are these financial models failing to explain excess returns? One obvious answer to this question which has been completely ignored is that the proxy being used to define risk is wrong. It is the contention of this proposal that investors are concerned about buying into an asset and subsequently experiencing a sequence of below average or negative returns. Under this premise, using the variance of returns as a measure of risk is inadequate and a new risk measure must be derived. This study demonstrates that measuring the deviation of an investor's wealth level from buying a risky asset in relation to what an investor's wealth level would have been from buying a risk-free asset discerns both the deviation of returns and the propensity of returns to sequence. It is then shown that sequencing risk and the slope of the term structure are integrally related. Specifically, the steeper the yield curve, the greater sequencing risk will be priced since a negative sequence could result in forced borrowing by investors when rates are high to maintain a constant consumption rate. Empirically, it is shown that measuring an asset's risk by the contribution it makes to a portfolio's propensity to sequence rather than to a portfolio's variance more accurately explains portfolio returns within a CAPM type framework. Additionally, size does not usurp the explanatory power of this new beta. Surprisingly, it is found that the explanatory power of the traditional beta and size are contingent upon the slope of the term structure being fairly flat. The wealth beta seems to be unaffected. The conclusion of the study suggests that current financial models are seriously flawed due to the erroneous definition and mis-measurement of risk. / Ph. D.

Evidence of changing patterns of food consumption behavior is presented. Previous attempts at explaining these changes are critically reviewed and the need for an alternate approach is identified. A model of consumer behavior in which utility from food consumption is maximized subject to outlay for foods and limits on the consumption of fat, cholesterol, sodium, and/or other food components is proposed. This model yields a system of demands that are functions of prices and outlay as well as the composition of food and limits on the consumption of these components. The structure of this model is examined and restrictions on consumer food demands are derived. The derivation of individual demands based on the proposed model is demonstrated using a specific indirect utility function. Tests of the joint hypotheses that fat or cholesterol consumption determines food demand are defined. The computation of aggregate food demand elasticities with respect to changes in prices and changes in attributes such as fat or cholesterol consumption is demonstrated. Data necessary for estimating the parameters of the model and testing hypotheses are identified. The model proposed in this study allows tests of the hypothesis that food demands are not affected by food composition as well as measurement of these effects / Ph. D.

This dissertation is a collection of essays on bids and offer matching in a labor market for new entrants to white-collar jobs. The papers compare some of the different institutions for determining wages and conducting the hiring process in the market for new entrants to white collar jobs. The first essay analyzes how does a firm announce and commit to a wage prior to deriving specific information about applicants' productivity and the consequences of following this hiring process. In the model there are two firms and at least as many applicants as the number of firms. All applicants apply simultaneously to both firms in response to the job advertisement which also mentions a wage. Each firm derives the firm-specific productivity of the applicants from their applications which is private information to each firm. None of the applicants have any information about the firms' evaluation. There are four pure strategy Nash Equilibria in wage announcements. Both firms announce a high wage, both firms announce a low wage, both firms announce a high or a low wage, and one firm announces a high wage and the other firm announces a low wage. In the latter case there also exists a unique mixed strategy equilibrium reflecting a firm's uncertainty about the choice of the other firm. In equilibrium one or both firms may not hire and the equilibrium may not exhibit wage dispersion. The second essay analyzes the question; which is better, to announce and commit to a particular wage prior to deriving specific information about applicants' productivity or to offer wages privately after deriving the firm-specific productivity. The equilibrium policy, to be followed by the firms in the first place, is determined endogenously by comparing the ex ante expected profits associated with the equilibria under the different policies. Lack of prior information and the uncertainty about the possible match results in "offer wages privately" as always an equilibrium policy. However, if a low wage is the equilibrium strategy under all the policies, then "any pair of policies" is an equilibrium. This justifies one of the circumstances in which different policies might coexist. In equilibrium a firm's position is always filled and the equilibrium outcome may not exhibit wage dispersion. The third essay analyses the question, if "announcing a wage" is the strategy rule to be followed by the firms, then what should be the equilibrium timing of wage announcement, before or after receiving specific information about applicants' productivity. Two policies are compared. Under the first policy a firm announces and commits to a particular wage prior to deriving the match-specific productivity. Under the second policy a firm solicits applications, derives the firm-specific productivity, and then announces and commits to a wage. The equilibrium timing of wage, to be followed by the firms in the first place, is determined endogenously by comparing the ex ante expected profits associated with the equilibrium strategy under the different timings. It turns out that announcing and committing to a particular wage after deriving specific information is always an equilibrium timing because of the informational advantage. However, if a low wage is the equilibrium strategy under all the policies then any pair of policies is an equilibrium. In equilibrium one of the firm's position may remain unfilled. The equilibrium outcome may not exhibit wage dispersion. / Ph. D.

In this study we look at the effects on economic growth of the continuous introduction of intermediate goods. Our theoretical framework enhances the endogenous growth theory, by allowing for participation in international trade. Furthermore, we test the behavior of the proposed theoretical model with data provided from the Penn World Tables. The theoretical part describes an economy in two different stages: first, we develop a model for a closed economy, and study the effects of the continuous introduction of durable goods. We show that the continuous introduction of durables causes sustained economic growth. We demonstrate that a more educated labor force contributes more to the growth of the economy. Second, we assume that trade takes place among similar countries. Both final and intermediate goods are traded, and we show that participation in international trade enhances the economic growth of this economy. We prove that with no restrictions to trade, countries continue to grow. Because we assumed that the countries were identical, we found that those countries that pursue the introduction of new durables will grow faster. In the empirical part, we test the proposed theoretical model. We want to test how the economic growth of this economy, is affected by the measures of exports and imports. We define the econometric method, and demonstrate empirically that there is a positive relation between the growth rate of an economy and the measures of exports and imports. Furthermore, the accumulation of physical capital has a positive effects on economic growth. We show that a positive relation exists between the available level of human capital and the growth rate of the economy. In our theoretical model, human capital is introduced indirectly through the efficiency of the labor force. We show that an educated labor force is preferred by the producers of final goods. We conclude that, other things being equal, poor countries that start with a relatively high level of human capital will grow faster. We also test our statistical model against the assumptions of normality, linearity, homoskedasticity, and homogeneity. We demonstrate that our statistical specification does not violate any of these assumptions. Thus, we can call our model a well-specified Statistical model. / Ph. D.

Theoretically, an equiproportionate change in prices and income should not affect the sales of products. This is known as the homogeneity of demand property on which the economic consumer demand theory is built. Rejection of this assumption is indicative of a state of mind called ‘money illusion’. Evidence from applied economics literature suggests that consumers respond asymmetrically to equal changes in prices and income. Such an asymmetry could be, among other things, due to the exclusion of marketing mix variables in their demand functions or inappropriate grouping of products. The main focus of the dissertation is to provide a theoretically consistent approach to include marketing variables in a sales response function. Specifically, advertising is hypothesized to act as a moderator in eliminating the asymmetry. A related issue investigated in this research is the existence and empirical testing of mental expenditure accounts. Grouping of products into mental expenditure accounts is thought to improve the homogeneity of demand. A system of equations is developed since the model involves prices and advertising of all products. The systems approach offers a consistent means to analyze sales when advertising programs interact; for example, orange juice advertising may affect the demand for milk and vice versa. The expenditure share system of equations is estimated using the Seemingly Unrelated Regression (SUR) estimation procedure to allow for dependence among error terms and cross-equation coefficients. Theoretically, this research tests the validity of the well established consumer demand theory. It provides an approach, consistent with neoclassical economic theory, to include marketing mix variables in sales response modeling. Managerially, this study helps in determining the level of advertising necessary to reduce the asymmetry in consumer response due to price and income changes. Substitution patterns obtained from the proposed analysis will aid managers to decide upon prices of closely related products within a category in the wake of income changes. The proposed model provides a methodology to explore and test market structure. / Ph. D.