Immigration

The calculated Israel series explained much of the observed increase but not all annual fluctuations. Israel's observed lifespan differential nearly doubled from 1990 to 2000 during a major immigration wave. The Israel model split the population into former Soviet Union immigrants and the rest of Israel's population. Large inflows from populations with high observed lifespan differentials can substantially change a host country's aggregate differential. The Israel immigration model depends on simplifying assumptions about retained origin mortality patterns, constant rates, and available origin data.