The problem of ecological correlation is now widely recognized but detailed analyses of the effects of aggregation on correlation and regression coefficients are rare. A short review of the aggregation problem is followed by an analysis of the specific effect of proximity aggregation on the slope coefficient of a bivariate linear model using data drawn from the Los Angeles Metropolitan region. The evidence suggests that changes in the slope coefficient are best related to the manner in which the covariation between the independent and dependent variables changes with increased aggregation. 相似文献
ABSTRACT. This paper analyzes 1963–77 manufacturing employment growth in the 48 contiguous states. Six factors jointly explain 96 percent of the variance. Markets explains 55 percent; climate, 15 percent; a rural state attraction, 11 percent; unionization, 6 percent; thresholds, 5 percent; and amenities, 4 percent. Resources, taxes, and business climate lack significance. Sunbelt-Frostbelt is a false dichotomy: the Northwest grew as fast as the South. The real contrast–largely caused by markets–is between growth rates of 6 percent in the Manufacturing Belt, 35 percent in its bordering Transition Zone, and 58 percent in the combined South and West. 相似文献
Binfield, P., Archer, M., Hand, S.J., Black, K.H., Myers, T.J., Gillespie, A.K. & Arena, D.A., June 2016. A new Miocene carnivorous marsupial, Barinya kutjamarpensis (Dasyuromorphia), from central Australia. Alcheringa 41, xx–xx. ISSN 0311-5518.
A new dasyuromorphian, Barinya kutjamarpensis sp. nov., is described on the basis of a partial dentary recovered from the Miocene Wipajiri Formation of northern South Australia. Although about the same size as the only other species of this genus, B. wangala from the Miocene faunal assemblages of the Riversleigh World Heritage Area, northwestern Queensland, it has significant differences in morphology including a very reduced talonid on M4 and proportionately wider molars. Based on the structural differences and the more extensive wear on its teeth, the central Australian species might have consumed harder or more abrasive prey in a more silt-rich environment than its congener, which hunted in the wet early to middle Miocene forests of Riversleigh.
