Private Provision of Public Goods under Delegated Common Agency

This paper considers a delegated common agent who produces a public good with private information regarding his cost. We show that truthful strategies are not optimal for principals, and that the agent enjoys some rent in equilibrium. It is not always that all principals make contributions: the number of contracts with positive contributions accepted by the agent in equilibrium is non-increasing as the agent becomes less efficient.

Syntactic Separation of Subset Satisfiability Problems

Variants of the Exponential Time Hypothesis (ETH) have been used to derive lower bounds on the time complexity for certain problems, so that the hardness results match long-standing algorithmic results. In this paper, we consider a syntactically defined class of problems, and give conditions for when problems in this class require strongly exponential time to approximate to within a factor of (1-epsilon) for some constant epsilon > 0, assuming the Gap Exponential Time Hypothesis (Gap-ETH), versus when they admit a PTAS. Our class includes a rich set of problems from additive combinatorics, computational geometry, and graph theory. Our hardness results also match the best known algorithmic results for these problems

Dependent k-Set Packing on Polynomoids

Specialized hereditary systems, e.g., matroids, are known to have many applications in algorithm design. We define a new notion called d-polynomoid as a hereditary system (E, ? ? 2^E) so that every two maximal sets in ? have less than d elements in common. We study the problem that, given a d-polynomoid (E, ?), asks if the ground set E contains ? disjoint k-subsets that are not in ?, and obtain a complexity trichotomy result for all pairs of k ? 1 and d ? 0. Our algorithmic result yields a sufficient and necessary condition that decides whether each hypergraph in some classes of r-uniform hypergraphs has a perfect matching, which has a number of algorithmic applications

The Allocation of Decision-Making Authority when Principal has Reputation Concerns

This paper analyzes the allocation of decision-making authority when the principal has reputation concerns. The principal can either keep the authority, or delegate it to the agent, who has better information. An outside evaluator who forms the principal's reputation cannot observe who makes the decision. The key feature of this paper is that the principal can in°uence her reputation through her delegation policy. With reputation concerns, we show that the principal tends to keep too much the authority from the evaluator's point of view, even though sometimes her information is not good enough for her to make the decision on her own.Decision-making authority, delegation, reputation concerns

Allocation of Decision-Making Authority with Principal's Reputation Concerns

This paper analyzes the allocation of decision-making authority when the principal has reputation concerns. The principal can either keep the authority and consult the agent (an expert), or delegate the authority to the agent; however, the outside evaluator cannot observe the allocation of authority. Hence, delegation can provide a way to manipulate the principal's ex post reputation. In general, the principal keeps the authority too often when she has the opportunity of delegation. When the evaluator believes that the agent may make the decision sometimes, the principal has less incentive to make the right decisionsDelegation, Principal's Reputation Concerns, Cheap Talk

Essays on Quantitative Methods for Consequences of Political Institutions

In this dissertation, I develop and apply sophisticated Bayesian models to the analysis of institutional effects on electoral and legislative behavior in the policy making process. Leveraging the flexibility of Bayesian methods for statistical modeling, I deal with several methodological problems encountered by political scientists, and social scientists in general, in some established research agenda. This dissertation shows the improvement of the ability to evaluate the success of conflicting theories when these methodological issues are properly dealt with. The consequences of political institutions are investigated at three different levels in this dissertation: countries, political parties, and individual legislators. First of all, at the country level, I investigate whether there is a difference between the performances of democratic and nondemocratic regimes in social provision policy in 18 Latin American countries by focusing on the rarely changing property of political regimes. An appropriate model for the dynamic nature of rarely changing variables is built to thoroughly explore how democratic institutions improve social welfare. Second, at the party level, I develop a Bayesian structural equation model to examine the interdependence between party policy strategies and party support in multiparty systems, in an effort to illustrate the endogenous dynamics of multiparty systems. The results show that party manifestos do not provide clear-cut division of party policy positions. Instead, party labels are more important information than changes in party manifestos to the electorate. Finally, at the level of legislators, I focus on the role of the president and political parties in Brazilian legislative process, in which political exchanges between the government and legislature is an essential feature. By recognizing the existence of the non-ideological effect on voting behavior, I develop a random item-difficulty ideal-point model implied by the spatial voting model to analyze the relationship between coalition dynamics and party-based voting behavior of legislators

Analysis and design of a wide dynamic range pulse-frequency modulation CMOS image sensor

Complementary Metal-Oxide Semiconductor (CMOS) image sensor is the dominant electronic imaging device in many application fields, including the mobile or portable devices, teleconference cameras, surveillance and medical imaging sensors. Wide dynamic range (WDR) imaging is of interest particular, demonstrating a large-contrast imaging range of the sensor. As of today, different approaches have been presented to provide solutions for this purpose, but there exists various trade-offs among these designs, which limit the number of applications. A pulse-frequency modulation (PFM) pixel offers the possibility to outperform existing designs in WDR imaging applications, however issues such as uniformity and cost have to be carefully handled to make it practical for different purposes. In addition, a complete evaluation of the sensor performance has to be executed prior to fabrication in silicon technology. A thorough investigation of WDR image sensor based on the PFM pixel is performed in this thesis. Starting with the analysis, modeling, and measurements of a PFM pixel, the details of every particular circuit operation are presented. The causes of dynamic range (DR) limitations and signal nonlinearity are identified, and noise measurement is also performed, to guide future design strategies. We present the design of an innovative double-delta compensating (DDC) technique which increases the sensor uniformity as well as DR. This technique achieves performance optimization of the PFM pixel with a minimal cost an improved linearity, and is carefully simulated to demonstrate its feasibility. A quad-sampling technique is also presented with the cooperation of pixel and column circuits to generate a WDR image sensor with a reduced cost for the pixel. This method, which is verified through the field-programmable gate array (FPGA) implementation, saves considerable area in the pixel and employs the maximal DR that a PFM pixel provides. A complete WDR image sensor structure is proposed to evaluate the performance and feasibility of fabrication in silicon technology. The plans of future work and possible improvements are also presented