An exact solution approach for vehicle routing and scheduling problems with soft time windows

A new column generation based exact optimization approach for the vehicle routing and scheduling problem with semi soft time windows (VRPSSTW) is presented. Elementary shortest path problem with resource constraints and late arrival penalties is solved as a subproblem, which rises from the Dantzig–Wolfe decomposition method. Exact solutions of VRPSSTW and hard time windows variant are compared on Solomon’s benchmark instances as well as on an instance based on Tokyo road network. It was found that the VRPSSTW solution results in fewer routes thus overall costs are reduced and late arrival penalties contribute only a small fraction to total cost.     

The performance of Japanese mutual funds

We analyze the performance of Japanese open-type stock mutualfunds for the 1981-1992 period. The results show that, regardlessof the performance measures and benchmarks employed, most ofthe Japanese mutual funds underperform the benchmarks by between3.6% and 10.8% per annum. These funds tend to invest more inlarge stocks with low book-to-market ratios. But this featuredoes not explain the underperformance. A potential explanationis the dilution effect caused by inflows of funds. In Japan,a new investor of an open-type fund only pays in the after-taxvalue of the net asset value. We conduct a bootstrap experimentto assess the magnitude of this dilution effect.     

A dynamic mobility model of individuals between jurisdictions in a system of local governments

This paper presents a dynamic mobility model in which individuals find incentives to move from one jurisdiction to another when they can enjoy a higher utility level by doing so, and inquires about welfare implications of the final outcome of such dynamic paths. The main conclusions are summarized as follows: (i) The mobility process of individuals is globally stable in the sense that the dynamic paths converge to the steady state equilibrium as time tends to infinity. (ii) There is a possible conflict between the principles of horizontal equity and Pareto optimality in the steady state of the dynamic system.     

Determinants of Underwriting Fees by New Entrant Banks: Evidence from the Japanese IPO Underwriting Market

This research investigates how banks expand market share after entering the underwriting market by examining the relation between commercial bank equity investments and underwriting fees. First, we find that not only bank underwriters with private information about issuers but also those without private information discount their fees, especially for smaller and riskier firms. This result is robust when using multiple firm‐bank relationship measures or when changing the investing stage. This is consistent with the strategic discount view that predicts that bank underwriters discount fees to expand bank market shares in underwriting markets.     

Do TV-aided model lessons in class improve student performance? Evidence from public primary schools in Papua New Guinea

Lack of access to high-quality education remains a serious concern in many developing countries. This is especially the case for rural areas, including islands suffering from a shortage of skilled teachers and sufficient educational equipment. We examine the impact of introducing TV-aided model lessons in class to enhance the quality of teaching (the EQUITV project) on the national examination test scores of Mathematics and “Combined Subject” (a comprehensive subject comprising 30% science and 70% social studies and other topics) as well as English in the final year of primary education in Papua New Guinea. We employ a panel event study to capture the different timings of the intervention across schools over multiple time periods. We find that the project significantly and robustly improved test scores for girls only in English 3 years after the introduction of the project, but no improvement was seen for boys.     

On the inclusiveness of rural road improvement: Evidence from Morocco

This paper explores the heterogeneous impact of a rural road improvement project on the economic activities and living standards of households in Morocco. Road pavement improvements are expected to promote better market access, encourage the transformation of traditional agricultural activities, and create opportunities for new economic activities. However, benefits may not extend evenly across different groups, and the distributional consequences call for careful empirical investigation. We employ a difference-in-differences (DID) estimation using a household-level panel dataset collected under a quasi-experimental setting in the 2010s. We classify households into three groups based on asset holdings (rich, middle, and poor). We provide several new findings. First, there was no significant transformation of agricultural production or sales for all groups. Second, rich households increased hired agricultural labor and began paid employment while middle households started new family businesses. Poor households, however, did not enjoy these new employment opportunities except for a marginal increase in family businesses. Third, due to shifts in employment, the rural road renewal project improved household consumption 3%–4% annually for rich and middle households, an impact not clearly seen among poor households. Thus, our findings show that the economic benefits of rural road improvement might not be well-inclusive.     

BOOK REVIEWS

Book Reviews in This Article: Seeds of Plenty, Seeds of Want: Social and. Economic. Implications of the Green Revolution by Andrew Pearse China's Transition to Industrialism: Producer Goods and Economic Development in the Twentieth Century by Thomas G. Rawski     

Transformation of international migrants in head wind: Evidence from Tajikistan in the 2010s

Tajikistan has relied on remittances by international migrants that have exceeded a quarter of annual GDP to date, despite a series of exogenous adverse events in the mid-2010s. We use a nationally representative panel dataset collected in 2013 and 2018 to explore the socio-economic characteristics of households with international migrants and migrants themselves. We provide several new findings. First, the prevalence of households with international migrants is 40%, with a substantial transition in migrant status during the research period. Second, households with international migrants are not poor, have Russian-speaking members, and are supported by an intense migration network. Third, younger, single, and more educated males comprise most of Tajikistan's international migrants. Fourth, households without Russian-speaking members or migration networks in 2013 had begun to send international migrants by 2018, while households in the richest group had exited from migration, suggesting s transition of the socio-economic composition of migrant-sending households during the mid-2010s.