Comments’ Extraction by User ID,Keywords, and Anchor Texts from the Thread of a Bulletin Board System

Bulletin Board Systems (BBSs) on the Web are used by many users posting comments on threads. Each thread carries a subject of discussion. Most users post comments related to a subject. However, unrelated comments are also posted. The unrelated comments distract users and diminish their understanding of the entire story of a thread. Comments unrelated to a subject have to be filtered automatically. This paper proposes a method that extracts comments related to a thread subject from a thread of BBS. The method extracts two types of comments: comments related to a thread subject (main comments), and comments related to main comments (sub-comments). The main comments are extracted by a user ID and keywords in the comments. The sub-comments are extracted by explicit and implicit anchor texts in the comments. We experimented with the proposed method and verified that comments extracted by the proposed method support participants in understanding the entire story of a thread.     

Why do first-born children live together with parents?

In this paper, we analyze the strategic residential location choices of multiple siblings who receive childcare assistance from their parents. Our three stage game yields a theoretical result that first-born children are more likely to live together with or close to their parents than second-born children, which is supported by our estimation results using Japanese micro-data. We also empirically show that the childcare assistance from parents is one of the determinants of the residential location choice of siblings. This paper is the first to succeed in explaining the residential location choice of siblings in Japan using economic incentives.     

Corporate Tax Reductions,Cross‐Border Ownership and Welfare

In this paper, a three‐country model incorporating the cross‐border ownership of stock and international firm relocation is constructed. Using this model, the effects of a reduction in the corporate tax on welfare in all three countries is examined. The findings indicate that if the country undertaking the reduction is moderately rich, and one of the two remaining countries is rich while the other country is poor, the tax reduction not only brings about a positive effect on its own welfare, but also increases the welfare of the rich foreign country and lowers that of the poor foreign country.     

ARE TELEVISION AND VIDEO GAMES REALLY HARMFUL FOR KIDS?

Are watching television (TV) and playing video games really harmful for children's development? By using a unique longitudinal dataset with detailed information on children's development and health, we examined the causal effect of hours of TV watched or of video games played on school‐aged children's problem behavior, orientation to school, and obesity. The results suggested that the answer to the question is yes, but the magnitude of the effect is sufficiently small to be considered as negligible. The results were robust to within‐twin‐fixed effects. (JEL I10, I20)     

Sales Strategy Mining Support with Visualization of Moving History

Strategic usage in data mining of sales data has come under increased focus as a result of the growth of data mining studies using electrical data, such as Point of Sale (POS) data. However, many of these mining systems only output results such as frequently appearing patterns, while, instead, they should be aimed at people who mine data. In this paper, a framework for leading and supporting new ideas from data is introduced. Based on this framework, a system that supports strategic usage in the data mining of sales data is proposed. The system deals not only with POS data, but also with the moving history of each customer. The system visualizes POS and moving history data, so that an analyzer inputs conditions to narrow down customers and acquires customer features. In addition to the ordinal outputs of a mining system, the analyzer interprets the meaning of his/her input and output to create a new strategy based on the framework. According to the experimental results, new strategies derived from the moving history were created.     

Auction Platform Design and the Linkage Principle

This paper examines an auction platform in which the monopoly platform maximizes profits by adjusting participation fees and choosing an auction format. The seller has private information on the quality of the good, and each participating buyer receives a private signal about his valuation of the good. The choice of auction format determines the allocation of trading surplus between the seller and buyers. This paper shows that when the seller's type is affiliated with the buyers' signals, the platform can charge higher participation fees on both sides by choosing a first‐price or descending auction than a second‐price or ascending auction.     

Heterogeneity of First-order Risk Aversion and the Equity Premium

I show that stockholders and non-stockholders can coexist in equilibrium even if securities markets are perfect and complete. This is due to a heterogeneous safety inclination, which is defined as heterogeneity in first-order risk aversion (Segal and Spivak, 1990). A static two-security market model is analysed by the mean–standard deviation approach, where safety inclination is described by the degree of the marginal rate of substitution between the mean and the standard deviation at a certain point. In equilibrium, aggregate shocks may be concentrated on stockholders, which may lead to a high equity premium.
JEL Classification Numbers: D81, E44.     

Effects of cost sharing on the demand for physician services in Japan: Evidence from a natural experiment

In this paper, we investigate the effects of cost sharing on the demand for physician services in Japan by using a natural experiment, namely, the increase in the coinsurance rate for household heads in 1997. Our primary finding from the two-year data, which includes the transitory effects of the reform, is that the effects of the reform on the frequency of physician visits were negative and statistically significant, and that the effects of the reform on expenditures per visit were also negative. Based on these results, the arc elasticity of demand for physician services is ?0.055. When we exclude the transitory period using the three-year data, the effects of the reform on the frequency of physician visits turn to be positive. It seems that the patients marginally curtailed the number of physician visits immediately after the reform; however, this effect was not sustained in the six months after the reform. We conclude that Japanese patients are not very price sensitive within the 10–20 percent range of coinsurance rate. Another important finding in our study is that the decrease in expenditure per visit retained even after the transitory period. This result suggests that the existence of a possible moral hazard in the treatment intensity although the decision-making process on the treatment intensity needs to be examined more carefully.     

Do environmental,social, and governance activities improve corporate financial performance?

This study investigated the relationship between corporate efficiency and corporate sustainability to determine whether firms concerned about environmental, social, and governance (ESG) issues can also be efficient and profitable. We applied data envelopment analysis to estimate corporate efficiency and investigated the nonlinear relationship between corporate efficiency and ESG disclosure. Evidence shows that corporate transparency regarding ESG information has a positive association with corporate efficiency at the moderate disclosure level, rather than at the high or low disclosure level. Governance information disclosure has the strongest positive linkage with corporate efficiency, followed by social and environmental information disclosure. Moreover, we explored the relationship between particular ESG activities and corporate financial performance (CFP), including corporate efficiency, return on assets, and market value. We found that most of the ESG activities reveal a nonnegative relationship with CFP. These findings may provide evidence about voluntary corporate social responsibility strategy choices for enhancing corporate sustainability.