Do U.S. Firms Have the Best Corporate Governance? A Cross-Country Examination of the Relation between Corporate Governance and Shareholder Wealth

We compare the governance of foreign firms to the governance of similar U.S. firms. Using an index of firm governance attributes, we find that, on average, foreign firms have worse governance than matching U.S. firms. Roughly 8% of foreign firms have better governance than comparable U.S. firms. The majority of these firms are either in the U.K. or in Canada. When we define a firm's governance gap as the difference between the quality of its governance and the governance of a comparable U.S. firm, we find that the value of foreign firms increases with the governance gap. This result suggests that firms are rewarded by the markets for having better governance than their U.S. peers. It is therefore not the case that foreign firms are better off simply mimicking the governance of comparable U.S. firms. Among the individual governance attributes considered, we find that firms with board and audit committee independence are valued more. In contrast, other attributes, such as the separation of the chairman of the board and of the CEO functions, do not appear to be associated with higher shareholder wealth.

Robust scheduling and robustness measures for the discrete time/cost trade-off problem

Cataloged from PDF version of article.Projects are often subject to various sources of uncertainties that have a negative impact on activity durations and costs. Therefore, it is crucial to develop effective approaches to generate robust project schedules that are less vulnerable to disruptions caused by uncontrollable factors. In this paper, we investigate the robust discrete time/cost trade-off problem, which is a multi-mode project scheduling problem with important practical relevance. We introduce surrogate measures that aim at providing an accurate estimate of the schedule robustness. The pertinence of each proposed measure is assessed through computational experiments. Using the insights revealed by the computational study, we propose a two-stage robust scheduling algorithm. Finally, we provide evidence that the proposed approach can be extended to solve a complex robust problem with tardiness penalties and earliness revenues. 2010 Elsevier B.V. All rights reserved

A methodology for solving single-model, stochastic assembly line balancing problem

Cataloged from PDF version of article.In this paper, a methodology is developed to solve the single-model, stochastic assembly line balancing problem for the objective of minimizing the total labor cost and the expected incompletion cost arising from tasks not completed within the prescribed cycle time. The methodology is based on determining an initial DP based solution and its improvement using a branch-and-bound procedure which uses an approximate solution instead of a lower bound for fathoming nodes. Detailed experimentation shows the superiority of this method over the most promising one from the literature. # 1999 Elsevier Science Ltd. All rights reserved

Why Did U.S. Banks Invest in Highly-Rated Securitization Tranches?

We estimate holdings of highly-rated tranches of mortgage securitizations of American deposit-taking banks ahead of the credit crisis and evaluate hypotheses that have been advanced to explain these holdings. We find that holdings of highly-rated tranches were economically trivial for the typical bank, but banks with greater holdings performed more poorly during the crisis. Though univariate comparisons show that banks with large trading books had greater holdings, the holdings of highly-rated tranches are not higher for banks with large trading books in regressions that control for bank size. The ratio of highly-rated tranches holdings to assets increases with bank assets, but not for banks with more than $50 billion of assets. This evidence is inconsistent with explanations for holdings of highly-rated tranches that emphasize the incentives of banks deemed “too-big-to-fail”. Further, the evidence does not provide support for “bad incentives” theories of holdings of highly-rated tranches. We find, however, that banks active in securitization held more highly-rated tranches. Such a result can be consistent with regulatory arbitrage as well as with securitizing banks holding highly-rated tranches to convince investors of the quality of these securities. Our evidence supports the latter hypothesis.

Conformal invariance and its breaking in a stochastic model of a fluctuating interface

Using Monte-Carlo simulations on large lattices, we study the effects of changing the parameter $u$ (the ratio of the adsorption and desorption rates) of the raise and peel model. This is a nonlocal stochastic model of a fluctuating interface. We show that for $0<u<1$ the system is massive, for $u=1$ it is massless and conformal invariant. For $u>1$ the conformal invariance is broken. The system is in a scale invariant but not conformal invariant phase. As far as we know it is the first example of a system which shows such a behavior. Moreover in the broken phase, the critical exponents vary continuously with the parameter $u$. This stays true also for the critical exponent $\tau$ which characterizes the probability distribution function of avalanches (the critical exponent $D$ staying unchanged).Comment: 22 pages and 20 figure

Increased oxidative stress associated with the severity of the liver disease in various forms of hepatitis B virus infection

BACKGROUND: Oxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. There is limited information about the oxidative status in subjects with hepatitis B virus infection. We aimed to evaluate the oxidative status in patients with various clinical forms of chronic hepatitis B infection. METHODS: Seventy-six patients with hepatitis B virus infection, in whom 33 with chronic hepatitis, 31 inactive carriers and 12 with cirrhosis, and 16 healthy subjects were enrolled. Total antioxidant response and total peroxide level measurement, and calculation of oxidative stress index were performed in all participants. RESULTS: Total antioxidant response was significantly lower in cirrhotics than inactive HbsAg carriers and controls (p = 0.008 and p = 0.008, respectively). Total peroxide level and oxidative stress index was significantly higher in cirrhotic (p < 0.001, both) and chronic hepatitis B subjects (p < 0.001, both) than inactive HbsAg carriers and controls. Total antioxidant response was comparable in chronic hepatitis B subjects, inactive HbsAg carriers and controls (both, p > 0.05/6). Total peroxide level and oxidative stress index were also comparable in inactive HBsAg carriers and controls (both, p > 0.05/6). Serum alanine amino transferase level was positively correlated with total peroxide level and oxidative stress index only in chronic hepatitis B subjects (p = 0.002, r = 0.519 and p = 0.008, r = 0.453, respectively). CONCLUSION: Oxidative stress occurs secondarily to increased total lipid peroxidation and inadequate total antioxidant response and is related to severity of the disease and replication status of virus in hepatitis B infection

Assembly line balancing using genetic algorithms

Assembly Line Balancing (ALB) is one of the important problems of production/operations management area. As small improvements in the performance of the system can lead to significant monetary consequences, it is of utmost importance to develop practical solution procedures that yield high-quality design decisions with minimal computational requirements. Due to the NP-hard nature of the ALB problem, heuristics are generally used to solve real life problems. In this paper, we propose an efficient heuristic to solve the deterministic and single-model ALB problem. The proposed heuristic is a Genetic Algorithm (GA) with a special chromosome structure that is partitioned dynamically through the evolution process. Elitism is also implemented in the model by using some concepts of Simulated Annealing (SA). In this context, the proposed approach can be viewed as a unified framework which combines several new concepts of AI in the algorithmic design. Our computational experiments with the proposed algorithm indicate that it outperforms the existing heuristics on several test problems