Inheritance, land, and capital mobility linked to labour mobility

This paper presents a two-country migration model, following Galor (1986), in which the world population consists of two types individuals. Individuals with a high (low) degree of altruism give to their children a high (low) level of bequest. Production uses three inputs: immobile land, mobile labour, and capital. Capital mobility is linked to labour mobility since individuals move with their inheritance. The model shows that countries are homothetic in the post-migration equilibrium with equal factor prices and equal densities of population. Migration flows are bilateral and the number of each type of migrants is uniquely determined. In some cases, migration leads to a Pareto improvement in both countries. Received: 8 July 1999/Accepted: 7 April 2000     

On private incentives to acquire household production skills

In non-cooperative family models, being good at contributing to family public goods like household production may reduce one's utility, since it tends to crowd out contributions from one's spouse. Similar effects also arise in cooperative models with non-cooperative threat point: improved contribution productivity entails loss of bargaining power. This strategic effect must be traded against the benefits of household production skills, in terms of increased consumption possibilities. Since cooperation involves extensive specialization, incentives to acquire household production skills are strikingly asymmetric, with the one not specializing in household production having strong disincentives for household skill acquisition. Received: 06 July 1999/Accepted: 08 June 2000     

认真贯彻十六大精神 ,切实加强高校党的建设

党的十六大提出全面建设小康社会,加快推进社会主义现代化,必须毫不放松加强和改善党的领导,全面推进党的建设新的伟大工程.我国高等学校在社会主义建设事业中的特殊地位和作用决定了高校党建工作的重要性和迫切性.必须高举十六大精神伟大旗帜,用邓小平理论和"三个代表"重要思想为指导,加强高校党的思想建设、组织建设和作风建设.     

Standing on the Shoulders of a Giant: Remembrances of Jack Michael,Part 2

In Part 1 of these remembrances of Jack Michael, we briefly described Jack’s history in terms of how he became a behavior analyst (Sundberg & Schlinger, 2021). We pointed out that he was one of the first to apply the principles of behavior analysis discovered in the experimental laboratory to the area of rehabilitation. In so doing, Jack was perhaps the first applied behavior analyst. In Part 1, some of his former students and close associates from his early years at the University of Houston, Arizona State University, and Western Michigan University—John Mabry, Grayson Osborne, Jon Bailey, Mark Sundberg, and J. Vincent Carbone—provided their personal tributes to Jack. In Part 2, we offer six more tributes that—with one exception, that of Ted Ayllon—provide insight into Jack’s work in the latter part of his career. In addition to Ted Ayllon, these tributes are from Jack’s students and close associates Hank Schlinger, Dave Palmer, John and Barb Esch, Carl Sundberg, and Caio Miguel. The authors provide insights not only into their views about Jack but also into their own lives. Collectively, they paint a picture of people from different backgrounds that all found their way to Jack Michael and to behavior analysis. To a person, they describe how their behavior, whether as scientists, practitioners, or both, was radically transformed as a result, and how they attribute that change largely to Jack’s influence.     

Jack Michael,Behavior Analyst

Jack Michael was the quintessential behavior analyst. Despite his reputation as a theoretician and expert in verbal behavior and on Skinner’s book Verbal Behavior, Jack was actually an applied behavior analyst in the literal sense before anyone had coined the term. Prior to becoming one of Jack’s doctoral students at Western Michigan University, I was a behavior-analytic neophyte. After I graduated and began my own teaching (modeled after Jack’s behavior-analytic method of teaching) and thinking and writing about behavior analysis, I found myself talking and thinking like Jack. He had a similar behavior changing effect not only on many of his other students, but also on others who had the good fortune to know him.     

苏俄、共产国际与陈炯明接触始末

20世纪20年代初,苏俄、共产国际在东方战略的指导下,通过各种渠道在华寻找政治同盟。南方实力派陈炯明资深的革命经历、对新生苏俄的赞美和尊崇、反帝爱国的政治态度曾一度使他成为苏俄、共产国际选择的联合对象。然而事实证明陈炯明并非莫斯科式的革命者,"六一六"事件发生后,陈氏对莫斯科和中共的态度也急转直下,苏俄、共产国际结束了联合陈炯明的尝试,从而转向与孙中山的合作。     

A review of statistical methods in imaging genetics

With the rapid growth of modern technology, many biomedical studies are being conducted to collect massive datasets with volumes of multi‐modality imaging, genetic, neurocognitive and clinical information from increasingly large cohorts. Simultaneously extracting and integrating rich and diverse heterogeneous information in neuroimaging and/or genomics from these big datasets could transform our understanding of how genetic variants impact brain structure and function, cognitive function and brain‐related disease risk across the lifespan. Such understanding is critical for diagnosis, prevention and treatment of numerous complex brain‐related disorders (e.g., schizophrenia and Alzheimer's disease). However, the development of analytical methods for the joint analysis of both high‐dimensional imaging phenotypes and high‐dimensional genetic data, a big data squared (BD²) problem, presents major computational and theoretical challenges for existing analytical methods. Besides the high‐dimensional nature of BD², various neuroimaging measures often exhibit strong spatial smoothness and dependence and genetic markers may have a natural dependence structure arising from linkage disequilibrium. We review some recent developments of various statistical techniques for imaging genetics, including massive univariate and voxel‐wise approaches, reduced rank regression, mixture models and group sparse multi‐task regression. By doing so, we hope that this review may encourage others in the statistical community to enter into this new and exciting field of research. The Canadian Journal of Statistics 47: 108–131; 2019 © 2019 Statistical Society of Canada     

Efficient and flexible model-based clustering of jumps in diffusion processes

Jump–diffusion processes involving diffusion processes with discontinuous movements, called jumps, are widely used to model time-series data that commonly exhibit discontinuity in their sample paths. The existing jump–diffusion models have been recently extended to multivariate time-series data. The models are, however, still limited by a single parametric jump-size distribution that is common across different subjects. Such strong parametric assumptions for the shape and structure of a jump-size distribution may be too restrictive and unrealistic for multiple subjects with different characteristics. This paper thus proposes an efficient Bayesian nonparametric method to flexibly model a jump-size distribution while borrowing information across subjects in a clustering procedure using a nested Dirichlet process. For efficient posterior computation, a partially collapsed Gibbs sampler is devised to fit the proposed model. The proposed methodology is illustrated through a simulation study and an application to daily stock price data for companies in the S&P 100 index from June 2007 to June 2017.     

Remittance volatility and financial sector development in sub-Saharan African countries

In this study we examine the relationship between remittances, remittance volatility and financial sector development in sub-Saharan Africa using a two-step system GMM estimator over the period 2002–2014. Separately focussing on banking sector- and stock market development, our study distinguishes between the effect of remittances and remittance volatility on financial sector depth and financial sector efficiency. The results indicate remittances act as a substitute for the formal banking system in sub-Saharan African countries. We further provide evidence that remittance volatility is detrimental to both banking sector depth and efficiency. No evidence is found that remittance volatility is related to stock market development. A policy implication from our study is that sub-Saharan African countries should have measures in place to monitor the predictability of remittances while the cost of remittance transfer needs to be investigated.     

Who will be idol? The importance of social networks for winning on reality shows

This paper examines, both theoretically and empirically, the effect of social networks and belonging to minority groups (or race) on the probability of winning in reality television shows. We develop a theoretical model that studies viewer behavior by presenting a framework of competition between two contestants from two different groups. The results are examined empirically using unique contestant data from the highly popular reality show “A Star Is Born”, the Israeli counterpart of “American Idol”. Our main finding is that social networks and belonging to minority groups play key roles in the contestant's victory. While the effect of belonging to a minority group is positive, the social network effect is U-shaped. Beyond the world of reality TV, this paper sheds light on the general behavior of social networks as well.