There are several reasons why people migrate known as push and pull factors, and they occur on economic, cultural, or environmental lines. Push factors are events and conditions that compel an individual to move from a location. Pull factors are conditions that influence migrants to move to a particular location. The number one reason why people migrate is for economic purposes. This is because people either get “pushed” away from where they live due to a lack of employment opportunities or pulled because somewhere else either offer more jobs/higher-paying jobs.

Cultural push factors usually involve slavery, political instability, ethnic cleansing, famine, and war. People who choose to flee or are forced to flee as a result of these problems are often refugees. The United States Committee for Refugees classifies a refugee as someone who has been forced from their homes and cannot return because of their religion, race, nationality, or political opinion. In 2010, the United Nations High Commission for Refugees estimated that there are over 44 million people worldwide that have been forcibly displaced. The number grows to another 27 million when considering internally displaced persons (IDPs). Cultural pull factors could include people who want to live in democratic societies, gender equality, or educational or religious opportunities.

There has been a dramatic increase in immigration into the United States from Latin America, Africa, and the Middle East. Some from these regions migrate to the U.S. out of economic necessity. Guest workers  (often also called transnational migration) are individuals who migrate temporarily to take up jobs in other countries; they plan to return to their home country.

Asylum seekers and refugees migrate to escape conflicts such as the civil wars in Somalia, Sudan, and Ethiopia. Genocides in Rwanda (1994) and, more recently, Darfur, Sudan have forced internal and international migration. The wars in Afghanistan, Iraq, Syria and Ukraine have also forced migration from these regions. For example, the U.N. High Commission for Refugees estimates  in June 2024 that over 6,483,500 people became refugees from Ukraine; most of these were forced into neighboring European countries. It is interesting to note that many such people who have been forced to flee their homes due to war, persecution or violence seek refuge in neighboring countries as crossing borders proves often difficult and costly. Here they will be housed in refugee camps which are temporary facilities built to provide immediate protection and assistance. The length of time people spend in refugee camps varies from between years to decades depending on how fast the conflict can be resolved. Internally displaced persons (IDPs) are people who had to leave their home but did not cross borders; they will also be housed in refugee camps. Normally, the number of such persons is higher than that of asylum seekers.

A variety of environmental push and pull factors also influence migration patterns. Environmental pull factors can include people wanting to live in particular environments. For example, many older adults like to live in Hawaii, Arizona or Florida because they prefer warmer climates and  the recreational opportunities that are provided for retired individuals. They are referred to as ‘snowbirds’ if they maintain homes in both their original northern area and in the south.  It appears that with the shift to home-office work many younger people join the older ones in their quest for a favorable climate. Some people want to live where snow activities are available or near an ocean. Push factors often are related to the frequency of natural disasters such as earthquakes, tsunamis, hurricanes, or flash floods that a region could experience. Consistent droughts, also influence migration patterns. A very recent example of this is the drought and famine in East Africa. As anthropogenic climate change becomes more pressing, and hundreds of millions of people become displaced, the world will see more climate migrants forced from their homes.

The United States Agency for International Development (US AID) and the Famine Early Warning System Network track potential famines globally so that relief organizations can have a heads up and be more proactive when events occur. People who have been pushed for environmental reasons are called environmentally displaced persons, sometimes also called ecological refugees. These refugees  face the problem that they are not protected or given the same rights under the 1951 Refugee Convention. Under the convention, a refugee is a person with: “well-founded fear of being persecuted for reasons of race, religion nationality, and membership of a particular social group or political opinion, who is outside the country of his nationality and, owing to such fear, is unwilling to avail himself of the protection of that country.” However, more and more people are becoming environmental refugees because of climate change, droughts, flooding from large storm systems, water shortages, and more.

3.2.2. Impacts of Migration

Besides low-skilled workers and refugees, a third category of immigrant has increased dramatically under globalization. Highly-skilled immigrants represent a unique contradiction. On the one hand, countries seek to increase border security, limit asylum seekers, and build walls. On the other, those same countries actively recruit and seek to attract immigrants with specific skills, training, and educational levels. Most commonly, wealthy countries like the U.K. regularly recruit nurses, scientists, and engineers from poorer countries to meet the needs of an aging population. As British residents have fewer children and society gets older, there is more demand specifically for healthcare workers of all kinds. As such, the best and brightest minds from poorer countries become attracted to the much higher wages outside of their countries and they leave—resulting in a brain drain. Nearly sixty percent of all doctors born in Ghana and eighty-five percent of nurses born in the Philippines have left the country to work elsewhere! Wealthy countries reap the benefits of this brain gain. Although highly-skilled and educated individuals and families that emigrate for higher pay undoubtedly benefit from emigration, the countries that experience brain drain persistently lose a very valuable resource. Besides losing most of its doctors, Ghana also now faces a major shortage of those qualified to teach the next generation of medical professionals, so the negative effect crosses multiple generations.

Check the 2017 Gross Brain Drain map displaying brain drain in the United States (scroll down a little) showing the pattern for overall or gross brain drain in 2017. Gross brain drain is the simple difference between the share of those that leave and those that stay in a state (excluding people who move there). The biggest losers, as you might expect, span the Rust Belt, adjacent parts of the Great Plains, the South-especially the Deep South-as well as Connecticut, Vermont, and New Hampshire.

Another consequence of migration is the phenomenon of remittances – money that is transferred by the migrants to send to their families or communities in their home countries. They can be in the form of cash or goods.

In 2019, most of the remittances were sent from the United States, followed by Saudi Arabia, Switzerland and Germany. For the top remittance recipients by amount (as of 2019) please check out this visual . In terms of absolute benefits, India and China are the greatest recipients. The second map shows the percentage the remittance is of the receiving country’s GDP; here it becomes obvious that countries with lower GDPs levels receive quite a large percentage in remittance payments indicating a high reliance on that money.