ON DECISION-MAKING FOR MAXIMUM PROFIT PER UNIT OF TIME FROM BATCH PRODUCTION

Finding ration sequences which result in maximum profit per day from fattening batches of livestock over successive weight intervals has posed difficulties in earlier studies. Fractional and dynamic programming are considered as solution methods and illustrated for a problem previously solved by total enumeration. Other problems are discussed which would be best solved by a combination of the two methods. A novel proposal is made for using the two methods to maximise the present value of returns from sequencing weight gains over infinite production cycles.     

The association between osteoporosis and patient outcomes in Japan

Objective To quantify the burden of osteoporosis and examine the interplay between osteoporosis and various comorbidities as it relates to patient outcomes.

Methods Data from the 2011 Japan National Health and Wellness Survey (NHWS; n?=?30 000), an internet health survey fielded to a nationally representative sample of the Japanese population were used. Only women between the ages of 50–90 years were included in the analyses (n?=?6950).

Results Compared with matched controls (n?=?404), patients with osteoporosis (n?=?404) had lower MCS scores (48.94 vs 51.63), PCS scores (45.57 vs 49.12) (all p?<?0.05). The presence of osteoporosis was associated with worse patient outcomes among those with hypertension, high cholesterol, and insomnia, among other conditions.

Conclusions The results suggest a significant quality-of-life and economic burden for patients with osteoporosis in Japan. Moreover, in a complex co-morbid environment, the presence of osteoporosis contributes more to patient outcomes than other chronic conditions.     

Wage distribution in Japan, 1989–2003

Abstract. This study examines the recent trend of the Japanese wage distribution based on a micro‐level data set from the Basic Survey on Wage Structure (1989–2003). We perform several decomposition analyses of changes in the distribution of the hourly wage. We observe that lower returns to education and years of tenure contribute to a diminishing income disparity between groups for both sexes. A larger variance within a group contributes to the wage disparity for males, while an increased heterogeneity of workers' attributes contributes to the wage disparity for females. The Dinardo, Fortin, and Lemieux decomposition confirms the basic findings with a parametric variance decomposition.     

Cordon Pricing and Land‐Use Regulation

This study explores the simultaneous imposition of cordon pricing and land‐use regulations in a continuous and closed monocentric city with homogeneous households. Results reveal the optimal level of a single cordon toll and its location and the optimal floor area ratio (FAR) regulation, clarifying what distortions remain in the existence of cordon pricing and FAR regulation. Among other results, this paper shows that, with an optimal cordon toll, FAR regulation should alternate between a minimum and a maximum regulation, both inside and outside the cordon line.     

Optimal Control of Pollution Accumulation with Long-Run Average Welfare

This paper considers the problem of pollution accumulation in order to maximize the long-run average welfare functional in environmental economics. We approach the problem by solving the associated Hamilton-Jacobi-Bellman equation in the classical sense, via the viscosity solution method. The optimal policy is shown to exist in a feedback from, and the maximum value is also obtained independently of the initial level of pollution. An equilibrium of the optimal stock of pollution is discussed.     

IS MINIMUM WAGE AN EFFECTIVE ANTI‐POVERTY POLICY IN JAPAN?

This paper considers whether the minimum wage is a well‐targeted antipoverty policy by examining the backgrounds of minimum‐wage workers. Whether raising the minimum wage reduces employment for unskilled workers is also investigated. An examination of micro data from a large‐scale government household survey, the Employment Structure Survey (Shugyo Kozo Kihon Chosa), reveals that approximately half of minimum‐wage workers belong to households with annual incomes of more than 5 million yen as a non‐head of household. A regression analysis indicates that an increase in the minimum wage moderately reduces the employment of male teenagers and middle‐aged married women, while it encourages the employment of high‐school age youth.     

REIT Stock Price Volatility and the Effects of Leverage

This article sheds light on several puzzling empirical observations. We examine the volatility implications of equity Real Estate Investment Trust (REIT) stock returns over the sample period from January 1985 through October 2012. We find a negative “leverage effect” in the pre‐ and post‐Greenspan era, but not during the Greenspan era (circa 1994–2006). We argue that the positive elasticity of variance with respect to the value of equity during the Greenspan era can be explained by a decline in the spread between the yield on commercial mortgages and 10‐year Treasuries, which triggered a wealth transfer from REIT equity holders to REIT debt holders. We also argue that the declining commercial‐mortgage‐10‐year‐Treasury yield spread during the Greenspan era allowed REITs to take on far more risk than most people realized. We then document that average REIT stock return volatility increased significantly in the 2007–2010 period in the midst of a historic decline in REIT stock prices. The results have significant implications for the good deal of interest and debate in the media over the status of REITs and whether equity REITs have become excessively risky relative to the returns they generate.     

Deregulation and labour earnings: Three motor carrier industries in Japan

We empirically examine the effect of product market deregulation on wages. The difference-in-difference approach is used with wage data from three motor carrier industries (the taxi, bus and trucking industries) in Japan to obtain the following findings. First, deregulations in the 1990s and 2000s caused the relative wages of taxi and bus drivers to decline, but this was not the case for truck drivers. Second, the large decline in the relative wages of taxi drivers can be explained by the deterioration of economic conditions; their wages are more sensitive to labour market conditions than those of drivers in other industries.