Market penetration by entry-exit dynamics

A generic characterization of the dynamics of market penetration by technological artifacts is here formulated on the basis of entry rate and exit rate considerations. It is shown that low-order reductions lead to the biologically based logistic dynamic, which—by empirical fit—has been found to be in very good agreement with numerous specific cases. In addition to the derivational justification of the logistic for artifact market penetration, we find that but a small number of parameters are involved in these autonomous characterizations suggesting therefore that market penetration may well be reduced to a similarly small number of dominant operative processes. Some nonautonomous extensions are also discussed.     

试论我国出口市场多元化战略实施

出口市场多元化应包括四个方面的内涵:首先,市场多元化是指区域多元化,即出口市场应全方位、多角度分布于世界各地,而不仅仅聚集于少数市场;其次是指商品多元化,因为商品是市场的核心内容,一国对外贸易,不单单是点多、面广,而且商品品种、规格、档次等都要多样化,才能符合不同消费层次的需求;第三,出口市场多元化应包括经营手段的多样化,即开拓海外市场要采取灵活多变的方式、方法。     

双旋Y切石英振子厚度模式的频温特性的研究

本文利用描述固体中弹性声波的克里斯托费尔方程,建立了双旋Y切石英振子厚度模式的频温特性分析方法,并编制了相应的计算机程序。该程序可给出双旋Y切石英振子在任意切角(ф_3ф_1)下的厚度模(a、b、c模)的频率温度特性曲线。文中给出了单旋AT切、BT切(b模)、双旋SC切(b、c模)、FC切、IT切、LC切、NL_1切、NL_2切、AK切等各已知切型的频温特性曲线。对石英谐振器的切角灵敏度和切角误差进行了分析。     

Explaining Differences in Economic Performance Among Racial and Ethnic Groups in the USA

A bstract . By utilizing self-reported race and ancestry in the 1980 and 1990 USA censuses and the Blinder-Oaxaca decomposition technique, the extent of wage discrimination experienced by women and by men is examined across 50 ethnic/racial groups. Systematic evidence of negative discrimination is revealed in both census years for Asian, Indian, black (African-American), Vietnamese, Cuban, Mexican, Puerto Rican , and Native American males. To assess the charge that the Blinder-Oaxaca decomposition indicates cultural rather than discriminatory differentials, two additional data experiments are performed—one that controls for color and varies culture, and one that controls for culture and varies color. Race appears to matter.     

Up in the Air: GTE's Experience in the MTA Auction for Personal Communication Services Licenses

In late 1994, GTE, one of the largest telecommunications firms in the world, entered an auction for the rights to provide personal communications services (PCS) using the electromagnetic spectrum. The administering agency, the Federal Communications Commission, adopted a novel multiple-round format for the PCS auction. The format presented GTE with a complex bidding problem. This article describes how the GTE bidding team answered the following question: Given its budget and valuations and the information available about rival bidders, how should GTE bid to achieve the best attainable outcome?     

Judo Strategy: 10 Techniques For Beating A Stronger Opponent

The idea of judo economics, building on analogies with the sport of judo, has been around for at least 20 years. But taking these ideas further to judo strategy means that a framework of strategic principles can be developed to help companies put stronger opponents on the mat.     

School Choice and the Distributional Effects of Ability Tracking: Does Separation Increase Inequality?

Tracking programs have been criticized on the grounds that they harm disadvantaged children. The bulk of empirical research supports this view, but existing studies compare outcomes across students placed in different tracks. Track placement is likely to be endogenous with respect to student outcomes. We use a new strategy for overcoming the endogeneity of track placement and find no evidence that tracking hurts low-ability children. Previous studies have also been based on the assumption that students' enrollment decisions are unrelated to whether or not the school tracks. When we account for the possibility that tracking programs affect school choice, we find evidence that they may help low-ability children.