Department of Statistics, University of Florida, Florida, USA.
Stat Methods Med Res. 2011 Feb;20(1):29-47. doi: 10.1177/0962280210370266. Epub 2010 Jun 2.
When a response variable Y is measured on one set of points and a spatially varying predictor variable X is measured on a different set of points, X and Y have different supports and thus are spatially misaligned. To draw inference about the association between X and Y , X is commonly predicted at the points for which Y is observed, and Y is regressed on the predicted X. If X is predicted using kriging or some other smoothing approach, use of the predicted instead of the true (unobserved) X values in the regression results in unbiased estimates of the regression parameters. However, the naive standard errors of these parameters tend to be too small. In this article, two simulation studies are used to compare methods for providing appropriate standard errors in this spatial setting. Three of the methods are extended to the change-of-support case where X is observed at points, but Y is observed for areal units, and these approaches are also compared via simulation.
当响应变量 Y 在一组点上进行测量,而空间变化的预测变量 X 在不同的点上进行测量时,X 和 Y 具有不同的支持,因此空间上不对齐。为了对 X 和 Y 之间的关联进行推断,通常在 Y 被观测到的点上预测 X,然后将 Y 回归到预测的 X 上。如果使用克里金或其他平滑方法来预测 X,则在回归中使用预测值(而不是真实的(未观测到的)X 值)会导致回归参数的无偏估计。但是,这些参数的天真标准误差往往太小。本文通过两项模拟研究比较了在这种空间设置中提供适当标准误差的方法。其中三种方法被扩展到了支持变化的情况,即 X 在点上被观测到,但 Y 是在面单元上被观测到,并且通过模拟比较了这些方法。