Innovation timing advantages: From economic theory to strategic application

First and second mover theory, as developed in industrial organization economics, maintains that firms can gain competitive advantage by using optimal timing in the introduction of innovations. Because the industry is the unit of analysis, the theory does not provide specific guidance for individual firms. We analyze the underlying sources of first and second mover timing advantages and clarify several issues regarding the basic theory. We then identify a variety of factors at the industry, firm and product/service levels and develop propositions showing their relations to individual firms in their efforts to benefit from timing advantages. We discuss the link which these indicator factors provide between economic theory and strategic timing choices. Finally, we suggest directions for research which would assist firms and their managers in selecting and pursuing innovation timing strategies.     

Leukemia Risk Associated with Benzene Exposure in the Pliofilm Cohort: I. Mortality Update and Exposure Distribution

The National Institute of Occupational Safety and Health (NIOSH) recently completed a vital status update adding 6 years of observation on the rubber workers known as the Pliofilm cohort. Using traditional standardized mortality ratio (SMR) analysis, we investigate the impact of the additional information gathered in the NIOSH update. We also compare the effect of using three sets of job-, plant-, and year-specific exposure estimates on the evaluation of benzene's leukemogenicity. The lack of any additional cases of multiple myeloma does not support trends toward elevated risks for this endpoint (as had been observed earlier), and there is no indication of increased incidences of solid tumors (as predicted by animal studies). Qualitatively, which exposure estimates are used does not alter the conclusions. The data added in the update did not greatly modify the estimated relative risk of leukemia associated with benzene exposure, but did confirm previous findings that occupational exposure to high concentrations had leukemogenic potential. The fact that leukemia has not been observed in any individual who started employment in Pliofilm production after 1950 suggests that the observed leukemia cases could be a response to very high levels of benzene exposure that occurred during the early years of this manufacturing process.     

Measuring the Effect of Tourism Services on Travelers’ Quality of Life: Further Validation

Neal, Sirgy and Uysal (1999) developed a model and a measure to capture the effect of tourism services on travelers quality of life (QOL). They hypothesized that travelers overall life satisfaction is derived from satisfaction with the primary life domains (e.g., family, job, health). Specifically, overall life satisfaction is derived from two sources of satisfaction, namely satisfaction with non-leisure life domains and satisfaction with leisure life. Satisfaction with leisure life is derived from satisfaction with leisure experiences that take place at home and satisfaction with travel/tourism experiences. Satisfaction with travel/tourism experiences results from satisfaction with trip reflections of the traveler (e.g., what the traveler remembers regarding perceived freedomfrom control, perceived freedom from work, involvement, arousal, mastery, and spontaneity experienced during the trip) and satisfaction with travel/tourism services. Satisfaction with travel/tourism services was hypothesized further to be derived from satisfaction with the service aspects of travel/tourism phases – pre-trip services, en-route services, destination services, and return-trip services. The model was tested using a study of university faculty and staff. The original model was extended by hypothesizing the moderation effect of length of stay. Specifically, we hypothesized that the relationshipsin the model are likely to be more evident in relation to travelers who have more time to experience the tourism services than those who do not. A survey of 815 consumers of travel/tourism services who reside in Southwest Virginia was conducted. As predicted, the data confirmed hypotheses as established in the original model. Satisfaction with tourism services affects travelers QOL through the mediating effects of satisfaction with travel/tourism experiences, and satisfaction with leisure life. Furthermore, the moderating effect of length of stay was confirmed by the data. In sum, this replication and extension study provided additional validational support of the original tourism services satisfaction measure in relation to QOL-related measures.     

The role of close friends in African American adolescents' dating and sexual behavior

This study examined the role of close friends in the sexual lives of African American adolescents. Fifteen African American adolescents residing in an urban neighborhood participated in individual in-depth qualitative interviews. The findings suggest that close friends play a critical role in the dating and sexual behaviors of inner-city African American adolescents, as they appear to serve as socializing agents that impact how adolescents conceptualize and socially construct dating and sexual roles and behaviors. Close friends also play a significant role in acquiring new dating and sexual partners and in determining the course of dating and sexual relationships. Although females and males expressed similar expectations regarding sexual fidelity and condom use, they differed with regard to their method and process of talking with friends about dating and sex, their shared social constructions about dating and sexual roles and expectations, and their perceptions of the meaning of dating. We discuss the implications of the findings in terms of involving close friends in interventions focused on improving the sexual health of African American adolescents. Future directions for research with African American adolescents and sexuality are also discussed.     

基于凸度的套期保值模型及分析

传统的债券久期和凸度的套期保值是非最优的,通过考虑国债期货和其最便宜交割债券之间定价关系推导了其正确的套期比率.套期比率方程明确表示了每种套期工具对对冲即期和远期利率风险的贡献,数值分析表明传统的套期方法存在过度套期.当(1)套期期限越长;(2)利率期限结构形状越陡峭;或(3)最便宜交割债券的息票率越高时,对高息票债券的过度套期程度越大.此结论对不同到期期限的债券和最便宜交割债券具有鲁棒性.     

Jocks, gender, race, and adolescent problem drinking

Alcohol remains the drug of choice for many adolescents; however, the nature of the relationship between athletic involvement and alcohol misuse remains ambiguous. In this article, we used a longitudinal sample of over 600 Western New York adolescents and their families to explore the gender-specific and race-specific relationships between identification with the "jock" label and adolescent alcohol consumption, specifically problem drinking. Operationalization of problem drinking included frequency measures of heavy drinking, binge drinking, and social problems related to alcohol (e.g., trouble with family, friends, school officials over drinking). Self-identified adolescent "jocks" were more likely to engage in problem drinking than their non-jock counterparts, even after controlling for gender, age, race, socioeconomic status, physical maturity, social maturity, and frequency of athletic activity. Jock identity was strongly associated with higher binge drinking frequency in Black adolescent girls. This study underscores the need to distinguish between objective and subjective meanings of athletic involvement when assessing the relationship between sport and adolescent health-risk behavior.     

Service and collaboration keys to physician control

Discover what physicians must do to regain power and half health care's slide from a profession toward a trade. The solutions lie in better customer service and improved physician collaboration.     

Fertility and development: evidence from Brazil

Using microdata from the Brazilian demographic censuses of 1960, 1970, 1980, and 1991, aggregated into 518 consistently defined spatial units called microregions, we estimated fertility and mortality and constructed indicators of development and living conditions in the rural and urban areas of the microregions in each census. We then estimated cross-sectional and fixed-effects models to answer questions about the degree to which changes in these indicators are associated with changes in fertility and whether the relationship between fertility and development shifts through time. We found strong and consistent relationships between the decline in fertility and measurable changes in social and economic circumstances.     

Rent Control: An Economic Abomination

Rent control is a public policy which fails on both normative and positive economic grounds. In the former case, it violates all canons of equity, of both right (private property rights are sacrosanct) and left (it does not promote egalitarianism, rather, often, it enriches rich tenants and impoverishes poor landlords). In the latter, it leads to inefficiency, deterioration of rental housing, reduces incentives for upkeep and maintenance, reduces labor mobility, exacerbates landlord tenant relations, promotes housing abandonment and homelessness, and misallocates resources away from residential rental units. This sovietization of housing has effects similar to the sovietization of anything else: farming, factories, industry, forestry, whatever. This revised version was published online in August 2006 with corrections to the Cover Date.