Three essays in bank mergers and market structure

I analyze the effects of bank mergers and competitive market structure after the Riegle-Neal Interstate Banking and Branching Efficiency Act. The first chapter studies the incentives to decide mergers and the effects of market competition. Nationwide branching from deregulation and the resulting bank consolidation have brought more a competitive market environment. In particular, branch networks play an important role in bank merger analysis. Using commercial banks' branch-level location data in Texas from 1994 to 2005, I estimate a two-sided matching model of merging and target banks with transferable utility. To study post-match values, I apply the maximum score estimator developed by Fox (2010). I find the positive assortative matching of bank sizes and I confirm that a bank prefers matching with target banks that have geographically overlapping markets. Moreover, I extend the standard matching model to incorporate externalities of market competition and the merger activities of rivals. Competitive rivals lessen the effects of mergers but mergers that increase market power have positive externalities on unmatched banks. The second chapter develops a structural model of demand and supply for retail banking to predict post-merger price. Ownership consolidation can affect not only price but also product characteristics. Once demand parameters and price elasticities are estimated, the adjustments in banking characteristics following mergers are considered in order to estimate marginal costs. I apply Peters’ (2006) simulation methods to account for the discrepancy between simulated merger changes and actual changes. The third chapter builds on an entry model of Berry and Waldfogel (1999) to quantify market competition. Significant consolidation waves after the Riegle-Neal Act brought a decrease in the number of banking institutions, while the relaxation of branching regulations almost doubled the number of bank branches and fortified market competition. When a new branch with high quality enters, I analyze the effects of market deposit expansion, business stealing from rival incumbent banks and cannibalization from other branches operated by the same bank. I find evidence that business stealing effects dominate cannibalization effects as market size increases. However, the impact of competition is localized and cannibalization effects are rather reversed at remote distances

Exercise-Induced Lymphocyte Apoptosis and Relationship with Level of Lactate in Smokers and Non-Smokers

Purposes of this study were 1) to examine the exercise intensity where lymphocyte apoptosis index (AI) is significantly increased in smokers and non-smokers, 2) to find out whether AI is associated with level of lactate (L). METHODS: Fourteen healthy untrained smokers (≥ 1 pack year, n=7) and non-smokers (n=7) aged 18 to 26 were recruited. Each subject conducted three treadmill runs at different intensities randomly. Running distance for all three runs was equivalent to 30 minute run at 70% VO2max. AI and L were analyzed at rest (Pre), immediately after (Post), and 1 h following (1 h post) each run. Data was analyzed using two way repeated measures ANOVA. RESULTS: Smokers showed higher AI than non-smokers at Post in 60% (12.5±0.62% vs. 9.97±0.51, p\u3c.008) and 70% VO2max running trials (17.53±0.57% vs. 15.6±0.41, p\u3c.018). All L values at post showed significantly higher than Pre and 1 h post, but there was no significant difference between smokers and non-smokers. The strong positive relationship between AI and L was detected (r=.739, smokers vs. r=.793, non-smokers). CONCLUSION: Smokers tend to have higher AI than non-smokers following runs at 60% and 70% VO2max, but not following a run at 80% VO2max. An increase in AI following a run at 60% VO2max indicates that lymphocyte apoptosis can be increased following moderate intensity exercise. Since L and AI at post were increased in dose-dependent manner to exercise intensity, it is suggested that an increase in lactate production during exercise might contribute to the increase in lymphocyte apoptosis

Anderson Acceleration for Partially Observable Markov Decision Processes: A Maximum Entropy Approach

Partially observable Markov decision processes (POMDPs) is a rich mathematical framework that embraces a large class of complex sequential decision-making problems under uncertainty with limited observations. However, the complexity of POMDPs poses various computational challenges, motivating the need for an efficient algorithm that rapidly finds a good enough suboptimal solution. In this paper, we propose a novel accelerated offline POMDP algorithm exploiting Anderson acceleration (AA) that is capable of efficiently solving fixed-point problems using previous solution estimates. Our algorithm is based on the Q-function approximation (QMDP) method to alleviate the scalability issue inherent in POMDPs. Inspired by the quasi-Newton interpretation of AA, we propose a maximum entropy variant of QMDP, which we call soft QMDP, to fully benefit from AA. We prove that the overall algorithm converges to the suboptimal solution obtained by soft QMDP. Our algorithm can also be implemented in a model-free manner using simulation data. Provable error bounds on the residual and the solution are provided to examine how the simulation errors are propagated through the proposed algorithm. Finally, the performance of our algorithm is tested on several benchmark problems. According to the results of our experiments, the proposed algorithm converges significantly faster without degrading the solution quality compared to its standard counterparts

A STUDY ON THE OPTIMAL DEFENSE POSITION OF HANDBALL GOALKEEPER: FACING A FORWARD JUMP SHOT MADE FROM 9M

The purpose of the study was to derive an optimal defense position for goalkeepers through calculating ideal defense area and actual defense area when blocking forward jump shots from 9 m distance. A total of 9 men's handball matches were captured with 4 digital video cameras from the 94th Korea National Sports Festival with consent from the Korea Handball Federation. Video clips with 78 forward jump shots from 9 m distance which included the whole movements of goalkeeper were analyzed. The ball's speed in the forward jump shot, release point of the ball, goalkeeper's defensive stance, and defensive position were analyzed. The actual defense position of goalkeeper was 1.10*0.37 m and the optimal defense position calculated through the movements of goalkeeper was 1.45 m from the goal line