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We analyze the endogenous firms' choice of organization form in the presence of endogenous freight rates, port fees with the public (or asymmetric) port ownership. We found that regardless of port ownership, one firm provides corporate incentives (i.e., U-form), and other firm provides divisional incentives (i.e., M-form). Thus, choosing U-form (resp. M-form) in the asymmetric organization for firm and producer surplus is profitable (resp. unprofitable), but for the government and consumer surplus is socially undesirable (resp. desirable). Furthermore, we present some extensions to check the robustness of the obtained results.

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This study develops a model to analyze the cost and profit structures faced by Independent System Operators (ISOs) and Demand Response Aggregators (DRAs) in South Korea's electricity demand response market. Based on this model, the study derives the socially optimal level of demand reduction and a settlement mechanism that maximizes overall welfare. In particular, to identify a compensation structure that minimizes operational costs while maintaining market participation incentives, the interaction between the hourly volatility of the system marginal price (SMP) and demand response participation levels is analyzed. Using hourly load and price data from 2023 onward, the model results suggest that expanding the volume of demand response beyond current levels and setting the settlement price at approximately 90--95% of the SMP can lead to a Pareto improvement. In this scenario, the ISO's market operation costs are significantly reduced, while the profits of DRAs increase. The magnitude of cost savings for the ISO varies with the time-varying elasticity of the SMP, whereas DRAs benefit from increased profits as the growth in demand response participation outweighs the slight decrease in settlement prices. These findings imply that sufficient incentives for market participation can be preserved even with moderate adjustments to the settlement ratio.

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This paper examines whether access to payday loans affects mortality, focusing on suicide among working-age adults. Payday lending has ambiguous welfare effects: short-term credit may help liquidity-constrained households smooth shocks, but high fees and rollovers can generate debt cycles and financial stress. The analysis combines cause-specific mortality from the National Vital Statistics System Multiple Cause-of-Death files (1994-2004) with county-year population counts from SEER, disaggregated by age, sex, and race, to construct suicide and cancer death rates of adults aged 19-64. Following citet{Melzer2011}'s border-based approach, the empirical strategy exploits a quasi-experimental setting in which Massachusetts, New Jersey, and New York prohibit payday lending but border states that legalize it; counties within 25 miles of a payday-allowing neighbor are classified as having de facto access. Difference-in-differences models with county and year fixed effects, complemented by staggered adoption event-study estimates, show no statistically significant effects of payday access on suicide rates overall or by age group. Placebo regressions for cancer mortality rates likewise reveal no systematic relationship with payday access.

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We study asymptotic properties of nonparametric coherence estimator at the zero frequency in the presence of over-differenced time series. It is found that when one series is over-differenced, the coherences at the origin decay to zero, regardless of the bandwidths for kernel estimation. On the other hand, when both series are over differenced, coherences at the zero frequency grow with the bandwidths, which lead to misleading interpretation of non-existent long-run relationships. Our simulation studies confirm the theoretical conjecture.