JAPAN'S SHIFT FROM PROCESS TO PRODUCT PATENTS IN THE PHARMACEUTICAL INDUSTRY AN EVENT STUDY OF THE IMPACT ON JAPANESE FIRMS

In 1975 Japan expanded the scope of its patent law by introducing product patents for newly developed chemical and pharmaceutical products. We use rate-of-return data from the Tokyo Stock Exchange for Japanese pharmaceutical companies to examine the impact of the change in the patent law. Our empirical findings indicate that the passage of the new patent law induced an excess return of approximately 26 percent to a portfolio of large pharmaceutical companies. Companies with R&D programs specializing in new product development experienced large gains, while companies with R&D programs specializing in imitative process patents experienced no gains.     

探寻武士道嬗变的轨迹及其民族学透视

日本武家文化背景下孕育产生的武士道精神,经过千年发展积淀,逐渐与日本民族文化融为一体,对日本民族产生了深远的影响,是日本民族精神的核心。近代蜕变成为军国主义的精神工具,引领日本走上了侵略扩张道路。     

THE SUPPLY OF INFANTS RELINQUISHED FOR ADOPTION: DID ACCESS TO ABORTION MAKE A DIFFERENCE?

Motivated by a theory of desired fertility I use three years of aggregate state level data to examine the impact of abortion access on the supply of infants relinquished for adoption. I show evidence that abortion access affected the supply of infants relinquished during the 1980s in two different ways. First, the availability of abortion providers has the expected effect of reducing the supply of infants relinquished, particularly relative to the demand for abortion. Second, abortion law has an unexpected negative effect. This suggests that as abortion laws become more restrictive the total number of unwanted births may decrease. ( JEL J13)     

Bayesian Non-Parametric Estimation of Smooth Hazard Rates for Seismic Hazard Assessment

Abstract.  Hazard rate estimation is an alternative to density estimation for positive variables that is of interest when variables are times to event. In particular, it is here shown that hazard rate estimation is useful for seismic hazard assessment. This paper suggests a simple, but flexible, Bayesian method for non-parametric hazard rate estimation, based on building the prior hazard rate as the convolution mixture of a Gaussian kernel with an exponential jump-size compound Poisson process. Conditions are given for a compound Poisson process prior to be well-defined and to select smooth hazard rates, an elicitation procedure is devised to assign a constant prior expected hazard rate while controlling prior variability, and a Markov chain Monte Carlo approximation of the posterior distribution is obtained. Finally, the suggested method is validated in a simulation study, and some Italian seismic event data are analysed.     

吸附制冷系统中吸附床的传热传质分析及结构设计

对化学吸附制冷系统中吸附剂颗粒之间以及整个吸附床的传热传质特性进行了分析，并总结了目前国内外强化吸附床传热传质性能的主要措施和方法．分析比较了两种用于化学吸附制冷的典型吸附床结构，在此基础上设计了一种新型的吸附床．     

One or two parents? Half or step siblings? The effect of family structure on young children's achievement

Do children who live with both biological parents fare better than children in other types of family structures? Does the presence of step or half-siblings affect child well-being? This study examines the effect of family structure on young children's achievement addressing two sources of potential bias: (1) misclassification of blended families and (2) the omission of within-family and individual time-invariant unobserved characteristics. The results show that family structure, when defined using traditional classifications, has little effect on young children's achievement test scores. When the definition of family type is expanded, living in a blended family and living in some types of single mother families, appears to have a small, unfavorable relationship with children's achievement.     

Maternal work hours and adolescents’ School outcomes among low-income families in four urban counties

We examine how changes in maternal work hours affect adolescent children's school participation and performance outcomes using data from interviews in 1998 and 2001 with approximately 1700 women who, in May 1995, were welfare-reliant, single mothers of adolescents living in neighborhoods of concentrated poverty in Cuyahoga (Cleveland), Los Angeles, Miami-Dade, and Philadelphia counties. Analyses control for a broad array of mothers' characteristics, including their psychological and physical health, experiences with domestic violence and substance abuse, as well as unobserved time-invariant characteristics. In fixed-effects models, we find unfavorable effects of increased maternal work hours on three of six outcomes: skipping school, performing above average, and parental contact about behavior problems. Adolescent-aged sons seem to be particularly sensitive to changes in mothers' hours of work.     

Objective Bayes Factors for Gaussian Directed Acyclic Graphical Models

Abstract. We propose an objective Bayesian method for the comparison of all Gaussian directed acyclic graphical models defined on a given set of variables. The method, which is based on the notion of fractional Bayes factor (BF), requires a single default (typically improper) prior on the space of unconstrained covariance matrices, together with a prior sample size hyper‐parameter, which can be set to its minimal value. We show that our approach produces genuine BFs. The implied prior on the concentration matrix of any complete graph is a data‐dependent Wishart distribution, and this in turn guarantees that Markov equivalent graphs are scored with the same marginal likelihood. We specialize our results to the smaller class of Gaussian decomposable undirected graphical models and show that in this case they coincide with those recently obtained using limiting versions of hyper‐inverse Wishart distributions as priors on the graph‐constrained covariance matrices.