A/HRC/11/7 page 5 on the move are affected at the pre-departure stage in countries of origin and in countries of transit and destination at the passage and arrival stages. Children in host countries are affected at the post-arrival and long-term stay and integration stages of the migration process. 19. Children can migrate in various ways. Children move across borders with their parents or are accompanied by extended family members or other adults and within mixed migratory flows.1 Children are also increasingly seeking migration opportunities to move across borders autonomously and unaccompanied. Falling prey to transnational organized crime and exploitation practices including smuggling, trafficking in persons and contemporary forms of slavery, which are described, in some instances, as abusive forms of migration,2 may also be a part of the migration experience for many children. 20. There is no accurate statistical information on the number of children involved in the international migration process.3 Age is not a common variable of disaggregated statistical data on international migration,4 which remains as the most difficult component of population change to measure.5 21. Like adult migration, child migration is influenced by the political, social, economic and environmental situation. This includes new global phenomena such as climate change, the food crisis and the financial and economic crisis.6 Child-specific phenomena such as child abuse and domestic violence may also influence the movement of children across borders. 1 Mixed migratory flows are defined as “complex population movements, including refugees, asylum-seekers, economic migrants and other migrants”. See International Migration Law, Glossary on Migration, International Organization for Migration, 2004, p. 42. 2 See, for example, the introduction by the United Nations High Commissioner for Human Rights to the Recommended Principles and Guidelines on Human Rights and Human Trafficking (E/2002/68/Add.1). 3 The United Nations Global Migration Database includes data from official statistical sources, that do not always include age as a variable for disaggregating data (http://esa.un.org/unmigration/). 4 Information available at the World Migrant Stock database includes five variables; age was not included among them. See World Migrant Stock: the 2005 Revision Population Database, available at http://esa.un.org/migration/. 5 See World Migration 2008: Managing Labour Mobility in the Evolving Global Economy, International Organization for Migration, 2008. 6 See The State of the World’s Refugees. Human Displacement in the New Millennium, Office of the United Nations High Commissioner for Refugees, 2006.