37 Emigration. Canada does not collect any statistics on emigration and the only indirect estimates of emigration available are provided by Statistics Canada. These estimates are calculated by the composite method based on administrative records on family allowances and taxation (Samuel, White, and Perreault, 1988). Beaujot and Rappak (n.d.) estimate that close to 25 percent of immigrants leave Canada within ten years of their arrival. About 60 percent of emigration results f..om the departure of immigrants and the rest from the departure of persons born in Canada. The departure rates of previous immigrants are generally highest for persons born in the United States and lowest for those born in Asia. As in the case of the United States, "many immigrants retain one foot in each of two countries" (Beaujot and Rappak, n.d.:2), so that emigration is not a clear-cut process.

As might be expected, migration tends to rise as imiligration increases (Beaujot and Rappak, n.d.). Nevertheless, in the mo.; recent population projections for Canada, emigration does not depend directly on the level of immigration. Emigration is fixed at a constant rate of 2.5 per thousand population (Statistics Canada, 1988). A constant rate may not be too unreasonable, however, since emigration of persons born in Canada should not depend on the level of immigration and since the emigration of immigrants depends more on the stock of immigrants than on recent flows. In fact, only about 25 percent of all emigration is attributable to immigrants who arrived in Canada in the previous five years (Beaujot and Rappak, n.d.).

Illegal Immigration. Illegal immigration is not numerically important in Canada and therefore, barring any change in this situation, it can be safely ignored in calculating net international migration. A 1983 study by the Canada Employment and Immigration Commission (1983) concluded that there were probably orly about 50,000 illegal immigrants in Canada, although some estimates tun as high as 200,000. Moreover, there are not any indications that net illegal immigration at the current time is an important factor in overall population movement.

Net International Migration. The official Canadian government estimates of net international migration for the period 1980-1987 are shown in Table 16. Because of the economic recession, the level of net immigration slumped from mid-1983 to mid-1986, but it rebounded again in the following year. For the five-year period from mid-1980 to mid-1985, the government estimates net immigration at 308,000 persons. In every year the majority of immigrants were estimated to be female and the majority of emigrants were estimated to be male. This results in a sex ratio of net immigra' s of 86.1, which is considerably lower than the sex ratio of 122.8 previously proposed by the World Bank.

Political Considerations. P.-cause of its current low levels of fertility, Canada faces eventual p-pulation decline and an aging populatior (Romaniuc, 1984). Canada has now had below-replacement fertility for 15 - and the current total fertility rate of 1.66 is about 20 percent lower thL. the level necessary to replace the population in the long-run (Taylor, 1987). A continued TFR of about 1.7 would require an annual immigration level of 275,000 persons by the year 2000 to maintain an annual growth rate of one percent, which is generally considered desirable for Canada (Taylor, 1987).