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When traditional methods for measuring economic welfare are scarce or unreliable, heights and BMIs are now well-accepted measurements that represent biological conditions during economic development. Weight, after controlling for height, is an additional measure for current net nutrition. Little is known about how weights varied among Mexicans living in the nineteenth century American West. Between 1870 and 1920, average Mexican weight was low and remained constant. Mexican farmers had the heaviest weights, and unskilled worker weights were low. Weight of Mexican-born individuals were higher than Mexicans born in the United States at low weights but lower at high weights. For combined characteristics, weight varied the most with age, an uncontrollable characteristic, indicating that nineteenth century Mexican current net nutrition varied the most with factors over which they had no control.  相似文献   
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Residential field courses are important and should be designed and delivered to maximize their value to students, staff and institutions. In this context, we use a novel approach involving analysis of the daily affective and conative reflections of students immersed in the field course experience to better understand student engagement with fieldwork. We show that students base their field course choice on a range of factors (costs and benefits) and that these choices subsequently influence student expectations and motivation to engage with fieldwork. We also show that the motivation of students to engage with fieldwork-based learning varies from person to person and from day to day. Our findings suggest that having a more nuanced understanding of the decisions students make when deciding which field course to enrol upon would enhance our ability to design attractive, accessible and useful field courses; that having an awareness of the expectations of students around field courses would enable us to better prepare them to undertake them; and that students are more motivated when they are afforded an opportunity to work independently and perceive themselves to have ownership of their learning.  相似文献   
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Despite its rich tradition, there are key limitations to researchers' ability to make generalizable inferences about state policy innovation and diffusion. This paper introduces new data and methods to move from empirical analyses of single policies to the analysis of comprehensive populations of policies and rigorously inferred diffusion networks. We have gathered policy adoption data appropriate for estimating policy innovativeness and tracing diffusion ties in a targeted manner (e.g., by policy domain, time period, or policy type) and extended the development of methods necessary to accurately and efficiently infer those ties. Our state policy innovation and diffusion (SPID) database includes 728 different policies coded by topic area. We provide an overview of this new dataset and illustrate two key uses: (i) static and dynamic innovativeness measures and (ii) latent diffusion networks that capture common pathways of diffusion between states across policies. The scope of the data allows us to compare patterns in both across policy topic areas. We conclude that these new resources will enable researchers to empirically investigate classes of questions that were difficult or impossible to study previously, but whose roots go back to the origins of the political science policy innovation and diffusion literature.  相似文献   
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