New, “big data” sources allow measurement of city characteristics and outcome variables at higher collection frequencies and more granular geographic scales than ever before. However, big data will not solve large urban social science questions on its own. Big urban data has the most value for the study of cities when it allows measurement of the previously opaque, or when it can be coupled with exogenous shocks to people or place. We describe a number of new urban data sources and illustrate how they can be used to improve the study and function of cities. We first show how Google Street View images can be used to predict income in New York City, suggesting that similar imagery data can be used to map wealth and poverty in previously unmeasured areas of the developing world. We then discuss how survey techniques can be improved to better measure willingness to pay for urban amenities. Finally, we explain how Internet data is being used to improve the quality of city services. (JEL R1, C8, C18) 相似文献
This paper deals with a research study sponsored by the Italian National Committee for Research (CNR), which involved the comparative analysis of 16 medium-large firms operating in a variety of technological and environmental conditions. The study analyzed the discontinuity and contingent nature of the planning process, and the relevance of tactical actions to adaptation. The comparative study demonstrated the impact of environmental change on the organizational structure and, to a certain extent, also on the form of strategic adaptation. A high degree of formality of the planning process did not appear to ensure an effective strategic formulation. 相似文献
We analyze the association between spouses’ earnings taking account of non-linearities along both spouses’ distribution of earnings. We also document the non-linearity of the relationships between earnings and labor force participation, earnings and couple formation, and earnings and number of children. Using simulations, we then analyze how changes in spouses’ rank-dependence structure, labor force participation and couple formation contribute to the upsurge in inequality in the U.S between 1967 and 2018. We find that an increased tendency towards positive sorting contributed substantially to the rise in inequality only among dual-earner couples, while it contributed little to overall inequality across households. Temporal and distributional heterogeneity are important, as earnings association had a more substantial role in the bottom of the earnings distribution and in recent years. The decline in couple formation contributed substantially to the rise in inequality, while the increase in female labor force participation and the fertility decline had equalizing effects.
We examine the effects of child policies on both transitional dynamics and long-term demo-economic outcomes in an overlapping-generations neoclassical growth model à la Chakraborty (J Econ Theory 116(1):119–137, 2004) extended with endogenous fertility under the assumption of weak altruism towards children. The government invests in public health, and an individual’s survival probability at the end of youth depends on health expenditure. We show that multiple development regimes can exist. However, poverty or prosperity does not necessarily depend on the initial conditions, since they are the result of how a child policy is designed. A child tax, for example, can be used effectively to enable those economies that were entrapped in poverty to prosper. There is also a long-term welfare-maximising level of the child tax. We show that a child tax can be used to increase capital accumulation, escape from poverty and maximise long-term welfare also when (a) a public pay-as-you-go pension system is in place and (b) the government issues an amount of public debt. Interestingly, there also exists a couple child tax–health tax that can be used to find the second-best optimum optimorum. In addition, we show that results are robust to the inclusion of decisions regarding the child quantity–quality trade-off under the assumption of impure altruism. In particular, there exists a threshold value of the child tax below (resp. above) which child quality spending is unaffordable (resp. affordable) and different scenarios are in existence. 相似文献
The transformed likelihood approach to estimation of fixed effects dynamic panel data models is shown to present very good
inferential properties but it is not directly implemented in the most diffused statistical software. The present paper aims
at showing how a simple model reformulation can be adopted to describe the problem in terms of classical linear mixed models.
The transformed likelihood approach is based on the first differences data transformation, the following results derive from
a convenient reformulation in terms of deviations from the first observations. Given the invariance to data transformation,
the likelihood functions defined in the two cases coincide. Resulting in a classical random effect linear model form, the
proposed approach significantly improves the number of available estimation procedures and provides a straightforward interpretation
for the parameters. Moreover, the proposed model specification allows to consider all the estimation improvements typical
of the random effects model literature. Simulation studies are conducted in order to study the robustness of the estimation
method to mean stationarity violation. 相似文献
AbstractObjective: Suicide is the second leading cause of death among emerging adults, yet little is known regarding their online help-seeking. Participants: The National Research Consortium of Counseling Centers in Higher Education's dataset (N=26,292). Methods: Students across the United States were recruited from 73 four-year institutions to participate during the 2010–2011 school year. Results: Observed the effectiveness of online and traditional help-seeking stratified by recent suicidal ideation related to their most distressful period in the past year. Females and younger students endorsed both types of help-seeking, yet those with recent ideation were less likely to disclose any help-seeking. Among those reporting recent ideation, only females reported that traditional supports were more than moderately helpful. Regardless of whether students endorsed ideation, students who were younger, engaged in risky behaviors and identified as females reported that online resources were more than moderately helpful. Conclusions: Online resources could potentially bridge barriers to traditional help-seeking for those reluctant to seek out care, yet traditional resources were reported to be the most effective among this sample. 相似文献
ABSTRACTThe purpose of this study is to explore the relationship between teacher beliefs pertaining to cultural diversity and their actual teaching activities. Using a model-based approach, this study looks at beliefs regarding diversity issues at both the theoretical and empirical levels. At the theoretical level, we attempt to systematise the many meanings of ‘beliefs’ found in the literature. At the empirical level, we examine the link between theory, beliefs, and teaching activities relating to diversity, using integrated analysis tools. To accomplish this, we used a qualitative methodological approach to examine the relationship between theory and practice in education. The sample consisted of 45 in-service primary teachers. The first results showed a gap between what teachers tend to say and what they actually do. We argue that future research needs to focus on the effects of teacher beliefs on teacher practice, with special attention devoted to the reflective process. 相似文献