introduction

The statistics in this section present a broad overview of international migration movements and of immigrant educational and labour market outcomes. As recently as five years ago, international statistical comparisons of immigrant flows and stocks would not have been possible, because the data required to present such an overview on a reasonably comparable basis either did not exist or existed only in a very partial way. In part this was due to the complexity of the national laws and regulations governing international migration movements. In recent years OECD has been working to be able to provide comparable data on migration related phenomena. The brief description which follows may be useful in understanding the nature of international migration.

International migration movements are almost always subject to restrictions. All OECD countries regulate the movements of non-nationals (non-citizens), to a greater or lesser extent. Only nationals (citizens) generally enjoy the right of free movement, both with respect to entry into or departure from their home country. In almost all countries, certain non-nationals are accorded the right of free entry and of stay for short periods, for example for tourism, as part of reciprocal agreements between countries. Most other non-nationals require an entry visa before they can enter the territory of a receiving state. The visa generally only accords the right to stay in the country for a short period of time, often three months. The right of free entry and stay may be extended, both in time and in scope, to include the right of residence and the exercise of an economic activity, either as part of regional agreements (Australia/New Zealand) or broader supra-national political or economic unions (the European Union).

The right of a non-national to stay or reside in a country for a more extended period manifests itself through the granting of a residence permit. The criteria considered in assessing whether or not to grant a permit generally includes the candidate’s reasons for wishing to stay in the country, which can include study, family reunification or formation, an extended visit, protection from persecution, employment or settlement. Persons granted a permit for reasons other than employment or settlement may or may not be authorised to exercise an economic activity in the country or may be authorised to do so on a limited basis. Certain types of movements (reunification with spouse and children or protection from persecution) are generally recognised human rights and are therefore generally not subject to interdiction, although some constraints may be placed on movements of this kind as well.

The duration of a residence permit will vary depending on the circumstances and/or reason for migration and the permit itself may or may not be renewable. Permit durations can vary from as little as three months for seasonal workers in some countries, one year for students or unskilled workers, more extended stays for the highly qualified or immigrants admitted for humanitarian reasons and indefinite duration in the case of settlement migration.

Countries differ significantly with respect to how longer term movements are treated. So-called "settlement countries”, namely Australia, Canada, New Zealand and the United States, grant the right of permanent residence upon entry to certain categories of immigrants, sometimes selected on the basis of their characteristics. In most other countries, the permit granted at entry is almost always a temporary one, even for immigrants whose stay in the country is likely to be indefinite. Over time, permits of longer duration are granted and eventually, the right to indefinite stay. Thus a temporary permit in these countries does not necessarily mean a temporary migration. In some cases, persons in the country on a restricted or temporary status, such as international students, may be allowed to change status and to enter the labour market or even to remain in the country indefinitely.

Certain migration movements can be unauthorised, either because persons enter a country illegally or enter legally but overstay beyond the period allowed them at the time of entry. Such entries are almost never covered in the immigration statistics. Unauthorised immigrants, however, may appear in data sources on the immigrant population (such as surveys or censuses), especially if there is no legal obstacle to, or penalty for, declaring oneself or following a legalisation process.

The type of regulations and constraints described here vary from country to country and affect the nature of the statistics produced and available. They make the production of comparable statistics on international migration a challenging undertaking.

See www.oecd.org/std/statisticsbrief: No. 9, July 2005: The Comparability of International Migration Statistics: Problems and Prospects.