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ABSTRACT. This paper analyzes 1954–1987 state manufacturing employment growth in 19 two-digit industries. Markets were found to be the strongest influence in 18 industries. Labor was the second strongest, followed by a threshold variable. Weaker influences were resources, taxes, and amenities. Regional values for the market, labor, and threshold variables corresponded well with regional employment change in the Manufacturing Belt and all other regions of the U.S.  相似文献   
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The conventional model of the relationship between welfare incentives and poverty rates holds that welfare payments produce an income-enhancement effect that removes families from poverty until some threshold. Beyond this point increased payments engender a work-disincentive effect resulting in increased rates of poverty. We challenge the model's assumption that poverty levels are a simple and spatially invariant response to welfare incentives, contending instead that local employment conditions may substantially alter the relation. Our reformulation of the conventional modeling approach is based on the expansion method. Specifically, we extend the model to include the effects of local labor-market conditions on the response of poverty levels to welfare incentives. In contesting the invariance assumption, the expansion method allows us to determine where and in what contexts welfare is “work discouraging.” The empirical analysis, which is undertaken at the county level, indicates that welfare payments vary in their influence on poverty rates across different employment contexts. A national map portraying this parameter instability demonstrates that female-family poverty rates are most responsive to welfare assistance in the rural South and least responsive in the metropolitan Northeast. Finally, we examine two sharply contrasting locales to illustrate how poverty is governed by specific employment and welfare characteristics.  相似文献   
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Innovation by "groping along," in which appointed public officials experiment during program implementation after little, if any, initial planning and analysis, has been promoted as a more accurate model of policy innovation than the rational comprehensive model of policy change. Analysis of two cases of environmental regulatory policy innovation suggests that administrative agencies may be more likely to follow the conventional model of the policy cycle when high levels of conflict are likely to accompany policy initiatives. The cases also suggest, however, that public officials will experiment during the innovation process when they are uncertain about the nature of the problem and the probable impacts of alternative solutions.  相似文献   
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Accelerator mass spectrometry radiocarbon ages have been taken for a test suite of small samples of material removed from some of the ‘beeswax’art figures found in rock shelters in northern Australia. The results indicate that we can reliably date this unique form of rock art with no noticeable damage. We had not expected to find figures of any great antiquity, and so we were surprised to find that the ages obtained spanned the time period from the recent past to about 4000 BP.  相似文献   
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A Roman archaeological site in northern Spain (La Maja, province of La Rioja) includes pottery workshops, part of an important ceramic industry that developed from about the first century BC to the first century AD. A geophysical study was planned to determine the extent of the industrial complex in the vicinity of an excavated kiln. Magnetic observations were done on a grid of 30 × 36m, with a sampling interval of 1m. Two dipolar-shaped anomalies were found: one in the north-east and the other in the south-west of the area. Low-pass and band-pass filters were used in the Fourier domain to enhance the characteristics of the magnetic data and to remove noise and undesirable shallow features. Three-dimensional polygonal prisms were used to model the magnetic anomalies based on palaeomagnetic measurements performed over an uncovered kiln that helped to constrain the induced and remanent parameters of the magnetizing fields.  相似文献   
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