The Economic Efficiency of Sampling Size: The Case of Beef Trim

The economically optimal sample size in a food safety test balances the marginal costs and marginal benefits of increasing the sample size. We provide a method for selecting the sample size when testing beef trim for Escherichia coli O157:H7 that equates the averted costs of recalls and health damages from contaminated meats sold to consumers with the increased costs of testing while allowing for uncertainty about the underlying prevalence rates of contamination. Using simulations, we show that, in most cases, the optimal sample size is larger than the current sample size of 60 and, in some cases, it exceeds 120. Moreover, lots with a lower prevalence rate have a higher expected damage because contamination is more difficult to detect. Our simulations indicate that these lots have a higher optimal sampling rate.     

LABOR‐MARKET HETEROGENEITY,AGGREGATION, AND POLICY (IN)VARIANCE OF DSGE MODEL PARAMETERS

Data from a heterogeneous‐agents economy with incomplete asset markets and indivisible labor supply are simulated under various fiscal policy regimes and an approximating representative‐agent model is estimated. Preference and technology parameter estimates of the representative‐agent model are not invariant to policy changes and the bias in the representative‐agent model’s policy predictions is large compared to predictive intervals that reflect parameter uncertainty. Since it is not always feasible to account for heterogeneity explicitly, it is important to recognize the possibility that the parameters of a highly aggregated model may not be invariant with respect to policy changes.     

UNEMPLOYMENT INSURANCE AND CULTURAL TRANSMISSION: THEORY AND APPLICATION TO EUROPEAN UNEMPLOYMENT

This paper emphasizes the two‐way causality between the provision of unemployment insurance and the cultural transmission of civicness. The returns to being uncivic are increasing in the generosity of unemployment insurance; but this generosity is decreasing in the number of uncivic individuals. In this context, I determine the evolution of preferences across generations and show that cultural heterogeneity is sustained over the long‐run. The dynamics of cultural transmission can generate a long lag between the introduction of unemployment insurance and an increase in people's willingness to live off government‐provided benefits. Hence, it offers an explanation to the ‘European unemployment puzzle’ due to the coexistence of generous unemployment insurance and low unemployment in the 1950s and 1960s.     

Can the Augmented Solow Model with Migration Explain the Italian Internal Brain Drain?

We extend the Dolado et al. (1994) model to both inflows and outflows of migrants and assume that they have a human capital endowment that contributes to increase/decrease the stock of human capital in the receiving/sending economy. We derive the conditional convergence equation in which the impact of migration flows on the growth rate is disentangled in a pure quantity effect and in a quality or composition effect of immigration and emigration rates that accounts for the relative human capital endowment of migrants with respect to resident population. Next, we test the model with Italian regional data for the 1970–2005 time period. We find that the model provides a good explanation of the Italian experience. The quantity effect is negative for the immigration rate and positive for the emigration rate, whereas the composition effect is positive for immigration and negative for emigration. Finally, we separate the centre‐north from the south and find that the composition effect of emigration is stronger for the latter. We interpret these results as a clear evidence of a brain drain from the Mezzogiorno to the centre‐northern regions.     

Immigration,Growth, and Unemployment: Panel VAR Evidence from OECD Countries

This paper examines empirically the interaction between immigration and host country economic conditions. We employ panel vector autoregression (VAR) techniques for a large annual data set on 22 OECD countries over the period 1987–2009. The VAR approach addresses the endogeneity problem by allowing for endogenous interactions between the variables in the system. Our results provide evidence of migration contribution to host economic prosperity (positive impact on GDP per capita and negative impact on aggregate unemployment, native‐ and foreign‐born unemployment rates). We also find that migration is influenced by host economic conditions (migration responds positively to host GDP per capita and negatively to host total unemployment rate).     

英汉动物习语中喻体的跨文化转换

本文阐述影响英汉习语中喻体异同的文化根源,并说明在翻译实践中怎样做好喻体的跨文化转换。     

论体育活动课与素质教育

通过对体育活动类课程的概念、特点及素质教育的本质、特征的阐述 ,明确了体育活动课程与素质教育的关系。以便在体育活动课程的教学过程中实施素质教育 ,推动我国体育课程研究和改革进程     

高等教育大众化背景下体育教育专业学生就业问题及发展对策研究

高等教育大众化使体育教育专业毕业生就业形式更加严峻,毕业生在就业问题上对自身定位不够、存在地区差异以及自身素养存在不足,同时受学历、毕业学校知名度、社会关系以及社会需求等因素的影响。解决好就业的问题应该从转变就业观念、提高就业竞争力、提高体育专业大学生的综合素质、调整专业课程结构设置、改革课程体系、加大高校就业指导工作的力度等方面入手。     

Pro/Engineer在工程制图教学中的应用

随着三维CAD技术的飞速发展和广泛应用，针对工程制图课程教学内容、教学方法及手段的特点，引入Pro/Engineer软件为实体建模工具，解决教学中出现的三维实体动态演示问题，探讨三维CAD软件在教学中的应用。     

利用课程资源推进体育创新

文章提出开发和整合各种体育课程资源，以丰富体育课堂教学内容，使体育课程更具趣味性，激发学生学习体育的兴趣，充分发挥课程资源优势，将学校体育延伸到终身体育，更好地达成体育课程目标．