One natural assumption to make is that areas with no MWS (FracMWS = 0) have no change in infant mortality. Since the MWS comprise roughly 30–35 percent of the population, this implies an aggregate reduction in infant mortality of roughly 2 per 1,000 births (30 percent × 6.5 = 1.95). This can be compared either to the World Development Indicators estimates of infant mortality rates of 15/1,000 in 2000 (suggesting a national reduction of 13 percent) or to the vital statistics sample mean of 6.2/1,000 in 2000 (suggesting a national reduction of ~ 30 percent).