A trend filtering method closely related to $$\ell _{1}$$ trend filtering

The filtering method developed by Kim et al. (SIAM Rev 51:339–360, 2009), \(\ell _{1}\) trend filtering, is attractive because it enables us to estimate a continuous piecewise linear trend. This paper introduces a new filtering method closely related to \(\ell _{1}\) trend filtering in order to contribute to the accumulation of knowledge on \(\ell _{1}\) trend filtering. We show that the piecewise linearity, which is the key feature of \(\ell _{1}\) trend filtering, is derived from the new filtering. For this reason, we refer to the filtering as ‘pure’ \(\ell _{1}\) trend filtering. We also demonstrate some other miscellaneous results concerning the new filtering.     

Mechanism design for a solution to the tragedy of commons

We consider the problem of the tragedy of commons in cooperative production economies, and propose a mechanism to resolve this tragedy, taking into account that the coordinator cannot perfectly monitor each agent’s labor skill and each agent may have an incentive to overstate as well as understate his own skill. Even in such a situation, the mechanism implements the proportional solution (Roemer in Soc Philos Policy 6:74–92, 1989 and Roemer and Silvestre in J Econ Theory 59:426–444, 1993) in Nash and strong equilibria when it is played as a normal form game. Moreover, the mechanism triply implements the solution in Nash, subgame-perfect, and strong equilibria when it is played as a two-stage extensive form game. We are greatly thankful to Semi Koray, William Thomson, and an anonymous referee of this journal for their concrete and helpful comments on improving the paper. An earlier version of this paper was presented at the annual meeting of the Japanese Economic Association held at Hitotsubashi University in October 2001 and at the Conference on Economic Design held at NYU in July 2002. We are grateful to Takehiko Yamato for his useful comments in the former conference. We are also thankful to Tatsuyoshi Saijo, Kotaro Suzumura, and Yoshikatsu Tatamitani for their kind comments.     

ACHIEVING FISCAL BALANCE IN JAPAN*

Japan is aging and has the highest government debt‐to‐output ratio among advanced economies. In this article, we build a micro data‐based, large‐scale overlapping generations model for Japan in which individuals differ in age, gender, employment type, income, and asset holdings, and incorporate the Japanese pension rules. Using existing pension law, current fiscal policy, and medium variants of demographic projections, we produce future paths for government expenditures and tax revenues, with implications for government debt and the public pension fund. Additional pension reform, a higher consumption tax, and higher female labor force participation help achieve fiscal stability.     

Stock price targeting and fiscal deficit in Japan: Why did the fiscal deficit increase during Japan’s lost decades?

The purpose of this paper is to explain why Japan’s fiscal deficit increased so dramatically in the 1990s and the 2000s. We focus on the role of “stock price targeting” to explain why the fiscal expenditure increased so much. After presenting a simple model to describe government behavior with an optimistic view about stock price and output growth, the paper tests whether the model can explain Japan’s fiscal expenditure. The empirical results, using biannual and high-frequency data of the 1990s and the 2000s, show that the stock price targeting can track Japan’s fiscal expenditure reasonably well, especially in the 1990s. They imply that without the stock price targeting, the total amount of biannual fiscal stimulus from 1992 to 2000 would have been lower by 2.5 trillion yen on average.     

Why Tour Guiding is Important for Ecotourism: Enhancing Guiding Quality with the Ecotourism Promotion Policy in Japan

The Ecotourism Promotion Policy in Japan requires tour guiding to be employed, although it provides little rationale for it. This paper reviews the literature to illustrate why tour guiding is important for achieving policy and ecotourism goals in order to support this requirement. An overview of ecotourism policy in Japan is provided, contributions of tour guiding to achieving the policy and ecotourism goals are described, and approaches to strengthening current practices along with the policy are discussed. It is suggested that non-profit organizations offer training to impart knowledge about guiding roles and interpretation at a national level and that ecotourism promotion councils teach knowledge about ecotour products and tourists at a regional level.     

Real interest rate equalization: some empirical evidence from the three major world financial markets

This article examines the linkage of real interest rates of the three major world financial markets (USA, Japan and the UK) with the use of cointegration methods. Unlike previous works, the investigation uses a trivariate vector autoregressive (VAR) model in which a constant term in the common stochastic trends space is excluded. Based on data generated after the liberalization of Japan's foreign exchange market at the end of 1980 (1981:1–1998:12), the article finds some empirical evidence indicating that the extent of the departure from the long-run real interest rate equalization (RIE) is not very large, although the null hypothesis of the long-run RIE is rejected in most cases.     

Application of Homotopy Analysis Method to Option Pricing Under Lévy Processes

Option pricing under the Lévy process has been considered an important research direction in the field of financial engineering, where a closed-form expression for the standard European option is available due to the existence of analytically tractable characteristic function according to the Lévy–Khinchin representation. However, this approach cannot be applied to exotic derivatives (such as barrier options) directly, although a large volume of exotic derivatives are actively traded in the current options market. An alternative approach is to solve the corresponding partial integro-differential equation (PIDE) numerically, which is, in fact, time-consuming and is not computationally tractable in general. In this paper, we apply the so-called homotopy analysis method (HAM) to solve the corresponding PIDE in a semi analytic form, being obtained from the following three steps: (1) Apply the Fourier transform to convert the PIDE to an ordinal differential equitation (ODE), and construct a differential system of ODEs. (2) Solve the system of ODEs, where each differential equation is shown to have an analytical solution. (3) Express the option price using the sum of infinite series, where each term may be expressed analytically and derived by applying Steps (1) and (2) recursively. To illustrate our technique more precisely, we take the variance gamma model as an example and provide the semi-analytic form. Numerical examples demonstrate a fast convergence of our proposed method to the prices of European and down-and-out call options with a few number of terms. Note that this method is easy to implement and can be applied to other types of options under general Lévy processes.     

A politically feasible social security reform with a two-tier structure

This paper investigates the welfare implications and political feasibility of social security reforms with a two-tier structure in Japan. We evaluate social security reforms from two points of view: (i) the ex-ante expected value of future generations, and (ii) whether current generations prefer reform to the status-quo system, which we call political feasibility. To evaluate the reforms, we use a large-scale overlapping generations model with idiosyncratic income risk and a two-tier structure. The first tier guarantees a basic pension and the second tier consists of the earnings-related part. Calibrating the parameters of the model to the Japanese economy, we compute the transition path and the two welfare criteria. We find that, given the two-tier structure in Japan, an increase in the basic pension and the abolition of the earnings-related part of the social security system improve the welfare of future generations, and ensures political feasibility when a consumption tax is the source of revenue.     

Bi-objective decision support system for routing and scheduling of hazardous materials

This paper presents a Pareto-based bi-objective optimization of hazardous materials vehicle routing and scheduling problem with time windows and shows its application to a realistic hazardous material logistics instance. A meta-heuristic solution algorithm is also proposed, which returns a set of routing solutions that approximate the frontier of the Pareto optimal solutions based on total scheduled travel time and total risk of whole transportation process. It works in a single-step fashion simultaneously constructing the vehicle route and selecting the optimal paths connecting the routed locations from a set of non-dominated paths obtained in terms of travel time and risk value.     

Predicting the intentions of tourism major students in a Korean University to acquire foreign language skills

The theory of planned behaviour was used to examine intentions of Korean tourism major students to acquire foreign language skills (FLS) and uncover the beliefs that contribute to that intention. Belief elicitation and belief measurement questionnaires were collected from 38 and 242 students at Woosong University in November and December 2010. Attitudes and subjective norms were found to be significant contributors to the sample students' intention to acquire FLS. Favourable attitudes and perceived social pressure should be maintained by targeting the behavioural beliefs and normative beliefs to heighten the intention level.