The data used in this report are based on four primary data sources from United Nations agencies: 1) estimates for the number of displaced persons (international migrants such as refugees and asylum seekers as well as internal migrants such as internally displaced persons) from the United Nations High Commissioner for Refugees (UNHCR), 2) estimates for the number of international migrants from the United Nations Population Division (UNPD), 3) estimates of Palestinian refugees living in Jordan, Lebanon and Syria registered with the United Nations Relief and Works Agency (UNRWA) and 4) total country population estimates from the World Population Prospects, 2015 revision from UNPD.

Defining displaced migrants

Displaced migrants in this report are a combination of internally displaced people, refugees and asylum seekers from the UNHCR database. Additionally, Palestinian refugees living in Jordan, Lebanon and Syria who are registered with UNRWA are also included. Data on displaced migrants are available for every year between 2005 and 2015, except for Palestinian refugees in 2015.

Estimates for Palestinian refugees rely on data from UNRWA for years 2005 through 2014. The 2015 estimate for Palestinian refugees living in Jordan, Lebanon and Syria is an extrapolation of Palestinian refugee population growth between 2013 and 2014 and may not reflect final estimates. Additionally, the number of Palestinian refugees living in Syria is constantly changing given the events occurring in that country. Palestinian refugees living in the Palestinian territories are not included in the estimates of this report. These refugees have not crossed international boundaries. For example, neither the United Nations High Commissioner for Refugees (UNHCR) nor United Nations migration statistics classify them as refugees or migrants. Neither does UNHCR consider Palestinian refugees living within the Palestinian territories to be internally displaced persons.

Defining non-displaced migrants

The number of non-displaced, international migrants in each Middle Eastern country was estimated by removing refugees and asylum seekers (including Palestinian refugees registered with UNRWA) from country totals of all international migrants found in the UNPD data. This remainder group of non-displaced migrants is assumed to be mostly economic migrants. This is a safe assumption given that the bulk of international migrants, once refugees and asylum seekers are removed, live in the six Gulf Cooperation Council countries (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and United Arab Emirates) known for employing millions of international migrants for various jobs. Figures for non-displaced international migrants in years 2006-2009 and 2011-2014 are estimates interpolated from UN estimates for 2005, 2010 and 2015.

All data sources are “stock” data. This means the data references total population at a certain point in time and does not measure flows. The UNHCR displaced migrant data includes the total stock of internally displaced persons, refugees and asylum seekers and those in refugee like situations as of the end of 2015. The UNPD data, both of international migrants and total populations, are mid-year estimates. Because of the different time frames, it is possible that estimates of the total number of migrants (displaced and non-displaced) and shares of total populations may not reflect actual population sizes in 2015.