A Taxi Zoning Analysis Using Large-Scale Probe Data: A Case Study for Metropolitan Bangkok

Taxis are considered one of the most convenient means of transportation, especially when people have to travel off-route, where public transportation is not a feasible option, and also when they need to reach a destination according to what is most convenient for them. However, many issues exist about taxi services, such as the problems of passengers who are unable to get taxi service at the location of their choice, or problems concerning when they need the taxi service to arrive. These problems may be due to the unavailability of the taxi at that particular location or due to the taxi driver not wanting to provide service. A taxi driver may not want to provide service to a potential passenger, because they may have preferences on the direction and areas they want to go or because of the different types of service zoning. Understanding the behaviors of taxi drivers and the characteristics of the trip/travel might be helpful to solving such issues. In this study, we conducted an analysis from a questionnaire survey and large-scale taxi probe data to understand taxi service behavior, travel characteristics, and to discover taxi service zoning characteristics. As a result, four types of taxi service zones including isolated zones, interactive zones, special service zones, and target zones were encountered. Travel characteristics were calculated and analyzed at different criteria, such as weekdays, weekends, and various time windows in a single day. The result of these characteristics was explained according to their similarities and dissimilarities in each type of zone. The discovery of the different zones and their respective definitions might be a good initiative for further development of a policy for taxi drivers to provide better service for passengers.     

Employment Adjustments in Japanese Firms During the Current Crisis

In this article we describe the severity of the current recession and depict the resultant harsh modes of employment adjustments. As a benchmark for comparison, we refer as frequently as possible to the recession that followed the first oil crisis. Macro indices include the extent of various employment adjustments, the roles of "shock–absorbing" industries, and the impact of public employment polices. As sources of micro–level data, we examine some 30 publicly owned, large–scale firms during both the current recession and the 1970s crisis. To further clarify the situation, we detail employment adjustments carried out by two "seriously wounded" firms.     

A Theoretical Reexamination of Privatization: Assessing its Welfare Impacts

Privatization has been one of the significant public policies adopted in the last two decades. Previous studies have focussed on efficacy gains at the firm and industry levels. This paper intends to reconsider the distributive impacts of privatization on the economy as a whole from a theoretical perspective. Specifically, it supposes an economy with two goods, two producers and two consumers, in which it is assumed that one of the consumers is not able to obtain one good that is regarded as a necessity. Since one basis of government intervention is to provide necessity to people who would not otherwise be able to obtain it, government intervention into production is assumed to satisfy this purpose. Using comparative statics, the paper analyzes how the welfare of two consumers is affected by this intervention, and shows that intervention can increase the welfare of some consumers and social welfare in general.     

Assessing the gains from deregulation in Japan's international telecommunications industry

The Japanese government terminated the monopoly of international telecommunications service by Kokusai Denshin Denwa (KDD) as part of the regulatory reform in telecommunications in 1985. Two new carriers entered the market in 1989. In defending its market share, KDD intensified cost reduction efforts and accepted lower profitability in order to carry out a series of sharp rate reductions. I have assessed the size of the net welfare gain associated with the deregulation. Deregulation brought about a 22.2% fall in KDD's unit cost for the eight-year period ending in 1992. Because this efficiency gain was fully passed along to telephone users in the form of lower rates, the corresponding increment of consumer surplus was of significant size, equivalent to 25.6% of total international telephone call revenues in 1992. (JEL L95, O53)     

Dynamic programming for non-additive stochastic objectives

We derive the existence of an optimum and the techniques of dynamic programming for non-additive stochastic objectives. Our key assumption for non-negative objectives is that asymptotic impatience exceeds asymptotic ‘mean’ growth, where ‘mean’ growth is derived not only from intertemporal inelasticity and the random return on investment but also from the curvature of the non-additive stochastic aggregator (i.e. the ‘certainty equivalent’). We provide broad families of new, interesting, and tractable examples. They illustrate that ‘mean’ growth can exist even when the distribution of returns has unbounded support, that power discounting often implies infinite asymptotic impatience, and that non-positive objectives are easily handled with few restrictions on growth.     

Construction of mixed-level supersaturated design

Supersaturated design is a form of fractional factorial design in which the number of columns is greater than the number of experimental runs. Construction methods of supersaturated design have been mainly focused on two levels cases. Much practical experience, however, indicates that two-level may sometimes be inadequate. This paper proposed a construction method of mixed-level supersaturated designs consisting of two-level and three-level columns. The χ² statistic is used for a measure of dependency of the design columns. The dependency properties for the newly constructed designs are derived and discussed. It is shown that these new designs have low dependencies and thus can be useful for practical uses.     

Informative advertising with spillover effects

This paper studies the effects of advertising in a Bertrand duopoly model, which extends Grossman and Shapiro (1984) by introducing the spillover advertising effect on top of the direct advertising effect. It is shown that the spillover effects would make the environment more monopolistic: higher prices and lower demand.     

A Characterization of the Dynamical System in a Two-sector Overlapping-generations Model: The Case of Unbounded Growth

This paper characterizes perfect-foresight equilibria in a two-sector overlapping-generations economy for the case of unbounded growth. The analysis demonstrates that gross substitutability in consumption is not sufficient to ensure the determinacy of equilibrium. Unlike Boldrin and Rustichini (1994), indeterminacy of equilibria can arise within the framework of an overlapping-generations model with convex technology. The finite time horizon of agents is the source of such indeterminacy.
JEL Classification Number: 041.     

The Contribution of Social Context to Participatory Planning Processes Within a Japanese Community

The concerns of diverse members in the community should be considered in the process of generating various alternatives. This requires a participatory process; a typical example being a small group discussion format such as a workshop. In small group discussions, understandability of participants’ opinions can be affected by the wording of their opinions. Our hypothesis in this study is, “The higher the similarity of wording between an expressed opinion and its wording in the media, the higher the likelihood of opinion adoption”. The hypothesis is examined and tested. In this study, we use the term “social acceptability” to denote the similarity of the wording of participants’ opinions with that used in media articles. To test this hypothesis, we proposed a methodology for evaluating the wording of a WS discussion and applied the methodology to the dialog data of two types discussions held in Ube, a Japanese city located in Yamaguchi Prefecture. Our analysis showed a positive correlation between social acceptability and adoption rate. To improve social acceptability, we suggest that a facilitator should frame the wording used by participants.