through 1999, we used a linear interpolation procedure described elsewhere (Grucza et al., 2014, 2012). Briefly, this was done by determining the weights for records representing each possible combination of covariate parameters in each Census data set (i.e., each combination of year, state, race/ethnicity, sex, age group and education). Weights for intracensal years were estimated as: [(2000-year)*(1990 weight) + (year-1990)*(2000 weight)] / 10). These data sets were obtained from the Integrated Public Use Microdata Series maintained by the Minnesota Population Center (Ruggles et al., 2010). This process is described in more detail in Part II of the Supplemental Material. Analyses to support the validity of this approach are described there as well.
