The Population Division of the Department of Economic and Social Affairs has released a new report titled "Replacement Migration: Is it a Solution to Declining and Ageing Populations?". Replacement migration refers to the international migration that a country would need to prevent population decline and population ageing resulting from low fertility and mortality rates.

   United Nations projections indicate that between 1995 and 2050, the population of Japan and virtually all countries of Europe will most likely decline. In a number of cases, including Estonia, Bulgaria and Italy, countries would lose between one quarter and one third of their population. Population ageing will be pervasive, bringing the median age of population to historically unprecedented high levels. For instance, in Italy, the median age will rise from 41 years in 2000 to 53 years in 2050. The potential support ratio - i.e., the number of persons of working age (15-64 years) per older person - will often be halved, from 4 or 5 to 2.

   Focusing on these two striking and critical trends, the report examines in detail the case of eight low-fertility countries (France, Germany, Italy, Japan, Republic of Korea, Russian Federation, United Kingdom and United States) and two regions (Europe and the European Union). In each case, alternative scenarios for the period 1995-2000 are considered, highlighting the impact that various levels of immigration would have on population size and population ageing.

   Major findings of this report include:

• In the next 50 years, the populations of most developed countries are projected to become smaller and older as a result of low fertility and increased longevity. In contrast, the population of the United States is projected to increase by almost a quarter. Among the countries studied in the report, Italy is projected to register the largest population decline in relative terms, losing 28 per cent of its population between 1995 and 2050 according to the United Nations medium variant projections. The population of the European Union, which in 1995 was larger than that of the United States by 105 million, in 2050 will become smaller by 18 million.
• Population decline is inevitable in the absence of replacement migration. Fertility may rebound in the coming decades, but few believe that it will recover sufficiently in most countries to reach replacement level in the foreseeable future.
• Some immigration is needed to prevent population decline in all countries and regions examined in the report. However, the level of immigration in relation to past experience varies greatly. For the European Union, a continuation of the immigration levels observed in the 1990s would roughly suffice to prevent total population from declining, while for Europe as a whole immigration would need to double. The Republic of Korea would need a relatively modest net inflow of migrants - a major change, however, for a country which has been a net sender until now. Italy and Japan would need to register notable increases in net immigration. In contrast, France, the United Kingdom and the United States would be able to maintain their total population with fewer immigrants than observed in recent years.
• The numbers of immigrants needed to prevent the decline of the total population are considerably larger than those envisioned by the United Nations projections. The only exception is the United States.
• The numbers of immigrants needed to prevent declines in the working-age population are larger than those needed to prevent declines in total population. In some cases, such as the Republic of Korea, France, the United Kingdom or the United States, they are several times larger. If such flows were to occur, post-1995 immigrants and their descendants would represent a strikingly large share of the total population in 2050 - between 30 and 39 per cent in the case of Japan, Germany and Italy.
• Relative to their population size, Italy and Germany would need the largest number of migrants to maintain the size of their working-age populations. Italy would require 6,500 migrants per million inhabitants annually and Germany 6,000. The United States would require the smallest number - 1,300 migrants per million inhabitants per year.
• The levels of migration needed to prevent population ageing are many times larger than the migration streams needed to prevent population decline. Maintaining potential support ratios would in all cases entail volumes of immigration entirely out of line with both past experience and reasonable expectations.
• In the absence of immigration, the potential support ratios could be maintained at current levels by increasing the upper limit of the working-age population to roughly 75 years of age.
• The new challenges of declining and ageing populations will require a comprehensive reassessment of many established policies and programmes, with a long-term perspective. Critical issues that need to be addressed include: (a) the appropriate ages for retirement; (b) the levels, types and nature of retirement and health care benefits for the elderly; (c) labour force participation; (d) the assessed amounts of contributions from workers and employers to support retirement and health care benefits for the elderly population; and (e) policies and programmes relating to international migration, in particular replacement migration and the integration of large numbers of recent migrants and their descendants.

The report may be accessed on the internet site of the Population Division (http://www.un.org/esa/population/unpop.htm). Further information may be obtained from the office of Ms. Hania Zlotnik, Director, Population Division, United Nations, New York 10017,USA; tel. +1-212-963-3179, fax +1-212-963-2147.