“…Thus the analyst has to estimate the population within the areas from the data aggregated across census tracts. This type of data estimation, that is, data transfer from the source zones to the target zone, is called areal interpolation (Lam 1983, Goodchild et al 1993, and there have been proposed a lot of areal interpolation methods in the literature (Wright 1936, Markoff and Shapiro 1973, Tobler 1979, Goodchild and Lam 1980, Lam 1983, Flowerdew 1988, Flowerdew and Green 1991, Goodchild et al 1993, Fisher and Langford 1995, Burrough and McDonnell 1998.…”