We estimate the impact of individual principals on school outcomes by using panel data that allow us to track principals over time. We find that individual principals have a substantive impact on school policies, working conditions, and student outcomes. In particular, students who attend a school that has a one standard deviation better principal improve their achievement by between 0.05 and 0.1 standard deviations. Despite rich background information on principals, it is difficult to characterize successful management, suggesting that innate skills are central. We find that the scope for discretion is larger among voucher schools and in areas with school competition. 相似文献
Since the United Nations’ establishment of the Millennium Development Goals (MDGs) in 2000 the world has observed an increasing trend in foreign aid provided by more affluent countries to developing nations. This paper examined whether foreign aid (total foreign aid and health sector aid) has been effective in improving the health of citizens in recipient nations since establishment of the MDGs. Five facets of population health were examined: infant mortality, life expectancy, the annual death rate, and immunizations against measles and diphtheria. Using a panel data set covering 90 developing countries, observed annually over 2001–2015, fixed-effects multivariate regressions with alternative specifications were estimated for each of these measures. The findings reveal that foreign aid has had little to no effect on population health since 2000. We found some evidence that foreign aid has improved life expectancy in developing countries, however, the effect is very small. In light of these findings, continued monitoring of the relationship between foreign aid and health outcomes would be both valuable and prudent.
A model analyzing the economics of sheep farming is formulated. The basic idea is simple. Sheep are capital and they are held by farmers as long as their capital value exceeds their slaughter, or meat, value. Farmers are therefore portfolio managers aiming to find the optimal combination of different categories of animals. Yields are compared with the yields from other assets. The model is formulated within a Northern Scandinavian economic and biological setting with a crucial distinction between the outdoors grazing season and the indoors season, and with adult sheep and lambs being different categories. In the first step, the management problem is analyzed with only the meat income of the farmers taken into account. In the next step, income from wool production is considered as well. The analysis provides several results that differ from standard harvesting theory. 相似文献
The U.S. Department of Agriculture operates several food assistance programs aimed at alleviating food insecurity. We study whether participation in both participation in both SNAP and WIC alleviates food insecurity compared with participation in SNAP alone. We bound underlying causal effects by applying nonparametric treatment effect methods that allow for endogenous selection and underreported program participation when validation data are available for one program (treatment) but not the other. We estimate average treatment effects using data from the National Household Food Acquisition and Purchase Survey (FoodAPS). FoodAPS includes administrative data to validate SNAP participation. Information on local food prices allows us to construct a food expenditure‐based monotone instrumental variable that does not require a typical instrumental variable exclusion restriction. Under relatively weak monotonicity assumptions, we identify that the impact of participating in both programs relative to SNAP alone is strictly positive, suggesting that the programs are nonredundant. This evidence can support improved design and targeting of food programs. 相似文献
Research has shown that offshore outsourcing processes may influence the behavior and strategic choices of firms, but little is known about the determining factors that influence the evolution and outcomes of those processes. Furthermore, longitudinal studies able to generate such insights are lacking. This paper suggests a detailed, activity-based approach to the study of the process of offshore outsourcing of high-value, advanced service activities. While earlier research has considered either firm-internal or firm-external sources of resource building, this study offers a more comprehensive theoretical model that combines resource-based theory and international business network theory. It aims to investigate how determinants of the offshore outsourcing process contribute to the resource stocks of client firms. Based on two longitudinal case studies of offshore outsourcing to India, the study finds that offshore outsourcing operations, in general, make positive contributions to the resource stocks of client firms. Some determinants contribute to the building of resources (partnership commitment decisions, knowledge creation and learning, trust building, the interconnectedness of resources) while others impede resource building (time compression diseconomies, lack of resource mass efficiencies). Notably, the interconnectedness among onshore activities, offshore activities and the underpinning knowledge resources reduces the risk of erosion of client firm resources, although this remains a long-term risk. 相似文献