Immigrant decisions concerning duration of stay and migratory frequency

"The temporary and repetitive character of contemporary labor migration is explained by assuming that immigrants have a preference for location. A life-cyle model of immigrant behavior is developed to determine net lifetime income, total time allocated to home-country and foreign-country residence, and the number of migratory trips. Because of income effects, home wages and foreign wages are not symmetric in their effect on the location of work effort. It is also shown that changes in travelling costs have predictable consequences for the number of border crossings, but not for the total time spent in the foreign labor market." The emphasis is on labor migration to developed countries.     

SIP墙板的综合性能分析

SIP墙板具有保温节能、施工方便和材料利用率高等优点,是一种综合性能很高的木结构复合材料。文章基于苏北速生杨木的已有科研及应用成果,通过参考轻型木结构的相关规程,针对SIP墙板的使用功能进行了讨论,评估该材料的综合性能并探讨了SIP墙板的综合设计方法。分析表明,SIP墙板轻质高强,具有良好的物理性能。     

Super returns to Super Bowl ads?

This paper uses a natural experiment—the Super Bowl—to study the causal effect of advertising on demand for movies. Identification of the causal effect rests on two points: 1) Super Bowl ads are purchased before advertisers know which teams will play; 2) home cities of the teams that are playing will have proportionally more viewers than viewers in other cities. We find that the movies in our sample experience on average incremental opening weekend ticket sales of about $8.4 million from a $3 million Super Bowl advertisement.     

An additively separable representation in the Savage framework

This paper proposes necessary and sufficient conditions for an additively separable representation of preferences in the Savage framework (where the objects of choice are acts: measurable functions from an infinite set of states to a potentially finite set of consequences). A preference relation over acts is represented by the integral over the subset of the product of the state space and the consequence space which corresponds to the act, where this integral is calculated with respect to an evaluation measure on this space. The result requires neither Savage's P3 (monotonicity) nor his P4 (weak comparative probability). Nevertheless, the representation it provides is as useful as Savage's for many economic applications.     

Diversified growth and competition: the experience of twelve large UK firms

This paper looks at the causes and competitive consequences enterprise diversification with reference to the experience of twelve large UK firms. It is noted although the majority of these firms diversified intially for defensive reasons, continuing diversification was often undertaken to enable the firm to maintain a satisfactory rate of earnings growth. In accordance with this goal, most of the twelve firms had acquired market leaders in diverse areas. A second conclusion therefore, is that diversification can add to the total market power available to the firm. The use of this power however, appears to depend upon the management philosophy and nature of resource allocation found within the firm.