An expected rank-size rule: A theoretical relationship between the rank size rule and city size distributions

This paper investigates a theoretical relationship between the rank-size rule and city size distributions. First, a method of relating a certain city size distribution to ranked city size is formulated by employing order statistics. Second, it is shown that there do not exist city size distributions which satisfy the rank-size rule. Third, an alternative rank-size rule is proposed as $\text{E(P}{}_{\mathrm{r}}\text{)?(r)}\text{?(r?y)}\text{=c}$, which is equivalent to the Pareto city size distribution. Last, an alternative statistical test for the rank-size rule is proposed to overcome a shortcoming of the conventional test. Along this line, the Hokkaido region data is analyzed.     

Markups,productivity and external market development of the service SMEs

During the last decade, economists and policy makers have extensively discussed what types of firms can exploit external markets by exporting and what happens to domestic firms if external competitors penetrate into the home market. Although both theoretical and empirical studies have been dedicated to these issues, few have been carried out for the service sector. Since the service sector accounts for the lion’s share of GDP, the lack of those studies indicates that a large part of the actual economy still remains veiled. Our study fills this gap. We examine whether or not the Melitz and Ottaviano (2008) model remains satisfied in the service sector, using data from Japanese SMEs. From our analysis, we confirm that larger market sizes are associated with higher productivity levels. On the other hand, firms with higher markups tend to develop their business in smaller markets, conditional of the simultaneity between production and consumption. These results reveal that further productivity growth in the service sector also requires markets to be larger and more integrated. In addition, the markup levels become lower in those markets.     

Evaluating the cost-effectiveness of secukinumab in moderate-to-severe psoriasis: a Japanese perspective

Aim: To evaluate the cost-effectiveness of secukinumab, a fully human anti-interleukin-17A monoclonal antibody, compared to other clinically used biologics (adalimumab, infliximab, and ustekinumab) in Japan for the treatment of moderate-to-severe psoriasis from the healthcare system (total costs) and patient co-payment (using different frequencies of drug purchase) perspectives.

Methods: A decision-tree (first year)/Markov model (subsequent years), with an annual cycle, was developed. The model adopted a 5-year time horizon. Efficacy inputs were obtained from a mixed-treatment comparison analysis, and other model inputs were collected from published literature and local Japanese sources. Model outcomes included quality-adjusted life years (QALYs) and an incremental cost-effectiveness ratio (ICER) in terms of cost per QALY gained. The annual discounting rate of 2% was applied to both costs and outcomes.

Results: Results for the healthcare system perspective showed that secukinumab had the highest number of quality-adjusted life years (QALYs) (4.07) vs other biologics, dominated ustekinumab and infliximab, and the ICER of secukinumab compared to adalimumab was ¥8,418,222/QALY gained. In the patient co-payment perspective with the monthly purchase of drugs, ustekinumab had the lowest co-payment cost, followed by infliximab, adalimumab, and secukinumab. In the patient co-payment perspective with a once every 3 months purchase of secukinumab and adalimumab, the co-payment costs of secukinumab, adalimumab, and ustekinumab became comparable, and infliximab had the highest co-payment cost.

Limitations: Only short-term efficacy data was modeled, as there was a lack of data on long-term outcomes. Treatment sequencing was restricted to first-line biologic treatment. Drop-out rates for comparators were assumed to be equivalent to secukinumab in the absence of available data.

Conclusions: Secukinumab is a cost-efficient treatment for moderate-to-severe psoriasis, providing greater health outcomes to patients at lower total costs compared to infliximab and ustekinumab, as well as comparable patient co-payment relative to other biologic treatments.     

A Bayesian Multivariate Risk-Neutral Method for Pricing Reverse Mortgages

In this article, we propose a Bayesian multivariate framework to price reverse mortgages that involve several risks in both insurance and financial sectors (e.g., mortality rates, interest rates, and house prices). Our method is a multivariate extension of the Bayesian risk-neutral method developed by Kogure and Kurachi. We apply the proposed method to Japanese data to examine the possibility for a successful introduction of reverse mortgages into Japan. The results suggest a promising future for this new market.     

On a Non-linear Risk Analysis for Stock Market Indexes

We propose a method to detect early signs of a potential major crash in the market from only the information of the time series representing its stock market data. As reinforcement of the abnormality test Test(ABN) developed in Okabe, Matsuura, and Klimek (International Journal of Pure and Applied Mathematics, 3, 443–484, 2002), we introduce in this paper a risk graph to measure abnormality of time series by using the non-linear prediction analysis in the theory of KM₂O-Langevin equations. By applying it to real data of stock market indexes on the Black Monday of 1987 and those during the past 7 years from January 2000 to December 2006, we investigate whether we can detect early signs of a potential major crash in the market by watching the behavior of the risk graph. An erratum to this article can be found at     

National culture and its impact on the choice of managing director in international production: the case of foreign firms in Greece

The aim of this study is to determine whether attitudinal differences between British and Japanese managers observed in the workplace can be attributed to culture or to the employment system. The findings provided substantial support for attribution to the employment system. Cultural differences between British and Japanese managers were not as large as the cultural thesis claims. The stereotyped cultural characteristics of Japanese managers - high social orientation at work and unconditional priority of work over family - were observed only in limited groups such as managers on the shop floor or senior managers. Attitudinal differences in the workplace were not simply the consequence of cultural differences, but rather to be understood as rational behavioural responses. Both British and Japanese managers' attitudes were considered to be a rational response to their employment systems.     

Productivity, returns to scale and product differentiation in the retail trade industry: an empirical analysis using Japanese firm-level data

This paper examines productivity and returns to scale under the assumption of monopolistic competition using Japanese firm-level data. Although differentiating products (services) is considered important in firms?? strategies and productivity growth, it has not been sufficiently investigated in previous studies. In this paper, we study this issue in two retail trade industries, department stores and supermarkets, applying the model of Melitz (2000). Our results indicate that the standard production function is not relevant to estimate productivity in imperfectly competitive markets. It also suggests that the market structure should be carefully considered in productivity analysis. In addition, product differentiation has a positive effect on firms?? revenue for the supermarkets. Furthermore, the retail trade industries possibly follow increasing returns to scale. Thus, policy measures that promote economies of scale and product differentiation should contribute to further growth in these industries. In addition, the results indicate that the regulatory reform of the retail trade industry in 2000 increased the gap between winners and losers in terms of productivity.     

Re-examining Cointegration, Unit Roots and Efficiency in Foreign Exchange Rates

This paper examines the cointegrating relationships in seven foreign exchange rates for a sample period from 1974 to 1991 by utilizing Johansen's (1991) method. Three subperiods are also examined to confirm the intertemporal stability of the test results. In addition, subgroups of the seven exchange rates are analyzed to determine the consistency of the empirical results with respect to different dimensions in the system. We find that the test results are sensitive to the choice of test statistics, time trends, subperiods as well as subgroups. All results indicate either one or no cointegrating relationship exists. Further, we study time series properties of twenty one cross-currency rates and the corresponding exchange rates in terms of a common currency. None of cross-currency rates are stationary and hence the pairs of exchange rates are not cointegrated.     

Forward Hedging the Exchange Risks of U.S. Equity Investments in the U.K., Germany and France

This paper simulates forward hedging of foreign exchange risks for U.S. investments in U.K., German and French equities. Rolling OLS and SUR regressions are used to obtain monthly exposure coefficients (hedge ratios), and the micro-market mechanics of the exchange rate bid-ask spread are considered throughout. While the coefficient of variation favors not hedging, no statistically significant differences are found between no hedge and hedge strategies. However, hedging produces a nontrivial incidence of cases where liquidated foreign equity values are less than amounts sold forward. The results, robust to rising and falling dollar sub-periods, do not support forward hedging.