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Leapfrog development is a typical form of sprawl. This paper aims at analyzing the existence, size, and persistence of leapfrogging in a dynamic urban economic model with endogenous green amenities. We analyze whether incoming households choose to settle at the fringe of the city or to jump further away depending on their preferences and the structure of the city. We first provide an analytical treatment of the conditions and characteristics under which a first leapfrog occurs and show how the optimal choice is affected by the size of the city, income, commuting costs, as well as the size of the area where green amenities are considered. We then study how further leapfrogging and multiple urban rings may appear and be maintained in the long‐run equilibrium, and how infill processes take place through time.  相似文献   
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Voluntary programs have emerged as important instruments of public policy. We explore whether programs lacking monitoring and enforcement mechanisms can curb participants’ shirking with program obligations. Incentive‐based approaches to policy see monitoring and enforcement as essential to curb shirking, while norm‐based approaches view social mechanisms such as norms and learning as sufficient to serve this purpose. The United Nations Global Compact (UNGC), a prominent international voluntary program, encourages firms to adopt socially responsible policies. Its program design, however, relies primarily on norms and learning to mitigate shirking. Using a panel of roughly 3,000 U.S. firms from 2000 to 2010, and multiple approaches to address endogeneity and selection issues, we examine the effects of Compact membership on members’ human rights and environmental performance. We find that members fare worse than nonmembers on costly and fundamental performance dimensions, while showing improvements only in more superficial dimensions. Exploiting the lack of monitoring and enforcement, UNGC members are able to shirk: enjoying goodwill benefits of program membership without making costly changes to their human rights and environmental practices.  相似文献   
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Since Marshall (1890), it has been widely held in urban economic theory that cities insure workers against the risk of unemployment by offering a larger pool of potential jobs. Using a large administrative panel data set on workers displaced as a result of plant closures, we examine whether positive effects from a higher urban job density are offset by more intense competition between workers. When controlling for the sorting of workers between regions, we find robust evidence that the effect of job competition on unemployment duration exceeds that of job opportunities in absolute value. Our results put the idea of urban risk-sharing into perspective and provide an explanation for observed longer unemployment durations in cities.  相似文献   
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The concept of “advocacy coalitions” is the bedrock of the Advocacy Coalition Framework (ACF), one of the most established and successful approaches for understanding policy processes across the globe. This article revisits and sharpens the conceptual definition of advocacy coalitions. We summarize the lessons from its theoretical emphases under the ACF and specify its five attributes (policy actors, shared beliefs, coordination, resources, and stability). Through this specification, we identify the ideal coalition type and several coalition subtypes. We then clarify and make a distinction between how we think about coalitions as a concept and how we approach coalitions empirically. This article sharpens the lens for describing and explaining coalitions toward better observations, theorizing, and measurements. It ends with next steps for further deepening and broadening knowledge about advocacy coalitions.  相似文献   
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Can age, period and cohort effects help explain support for Quebec sovereignty? Previous work on this question has focused mostly on the effects of age and cohort. We contribute to this debate by adding a period perspective. As such, our study is the first to investigate the impact of age, cohort and period effects in a single study of opinion towards sovereignty in Quebec. We take advantage of an original dataset that includes survey data collected between 1985 and 2012. We use these data to examine the impact of age, birth year and survey year on support for this constitutional option among francophone Quebeckers. Our results are in line with previous work: we show that younger Quebeckers are more likely to support sovereignty, and that some cohorts – namely, respondents born between 1945 and 1959 – are also more likely to favour this option. Perhaps more surprisingly, we find that specific events are comparatively the most important factor to explain fluctuations in Quebeckers' attitudes towards sovereignty.  相似文献   
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We analyse the isotopic values (δ13C, δ15N) of the diet of pre-Columbian horticulturalist populations from tropical and subtropical areas of southeastern South America, belonging to the Guarani and Taquara archaeological units. The data indicate different trends in each one (T?=?4.21; P?=?0.0004), showing a mixed diet with maize consumption in the Guarani samples (δ13Cco?=??15.5?±?1.8‰; δ13Cap ?10.4?±?0.8‰) and a depleted one in the Taquara ones (δ13Cco ?18.2?±?1.7‰; δ13Cap ?11.9?±?0.9‰), with a significant internal dispersion in both populations. The first population has higher nitrogen values (δ15N 11.1?±?0.6‰) compared to the Taquara samples (δ15N 9.3?±?1‰), suggesting a more carnivorous diet. The recognition of these pre-Columbian mixed diets involves the identification of maize cultivation on the Atlantic side of the southernmost area of South America (Parana Delta, 34° SL). Through the analysis of δ18O we have identified two isotopic ecozones, the first along the Paraná River Valley, with an average value of δ18O ?3.7?±?0.5‰ (CV?=?13.5%; CI?=??3.83 / ?3.16), and the second one, located in the Planalto of southern Brazil (Araucaria Forest), with a mean value of δ18O ?1.5?±?0.3‰ (CV?=?16.5%; CI?=??1.69 / ?1.29). The isotopic data (δ13C, δ15N and δ18O) suggest human movements between these two ecozones.  相似文献   
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