International migration is a phenomenon that touches a very high proportion of New Zealanders: about 20 per cent of New Zealand’s resident population of some 4 million were born abroad, and it is thought that over half a million citizens are resident in other countries. Unusually for an OECD country, issues relate to both immigration and emigration, as the causes and consequences of both these phenomena are important for NZ policymakers. Over the past 30 years, immigration has been largely balanced by emigration, with no substantial net impact on population change. But the net flow has been variable, with periods of large net immigration alternating with net emigration. Most recently there has been a rapid shift from net emigration (as recently as 1999-2000) to very high levels of net immigration. Issues for policy include whether – and how – policy might seek to moderate this variability, the extent to which immigration policy should be linked to the labour market situation or other factors, and whether emigration of New Zealanders should be seen as a problem or an advantage...