Macro Theories

Macroeconomic theories of internal migration use traditional variables with large scopes to explain migration flows. Macroeconomic theories discuss the impacts of country-wide variables, such as wages and employment, that are quantifiable and have clear, definable boundaries and are usually made of aggregate data.

Internal migration, according to macroeconomics, is almost always tied to wage differentials; internal migration is expected to follow a path from places with low wages to places with high wages. The common belief in macroeconomic internal migration is that wages will eventually equalize as people move from low-wage, low-demand markets to high-wage, high-demand markets, thus causing the initial location to transition from a low-wage, low-demand place to a high-wage, high-demand market over time and the opposite occurring for the initial high-wage, high-demand location.

Some macroeconomic theories concerning linguistic, ethnic, racial, and environmental differences are gaining more traction, but they are not standard. Macroeconomic theories also usually depend on ideal scenarios, such as the net migration rate, rather than realistic ones.

Additionally, human beings are complex, and macroeconomic theories have often been found lacking in providing definitive, reliable predictions and explanations for human activity. These shortcomings are remedied by the microbehavioral theory of internal migration.

Micro Theories

Microbehavioral theory focuses on more qualitative data that offers explanations, context, and possible influencing factors as contracted with macroeconomic theories, but it still utilizes quantitative data, such as census information.

As explained by microbehavioral theory, internal migration is influenced by variables such as human capital, pulls and pushes for locations, and residential mobility. On the micro level, internal migration looks at human or regional scale data, utilizing person-specific datasets like the census or residential histories. It purports that people only consider subsets of options rather than weighing all possible factors when migrating internally, and it provides differentiation behind the motivation for migration.

One reason for internal migration is economic, the primary factor considered by macroeconomic theories. Other possible motivators include pushes from their original location, pulls to a certain destination, employment, housing, and other socioeconomic changes.

Specific characteristics of a population can be studied against internal migration flows, and influencing factors, such as gender, age, and race, can be controlled for. Because microbehavioral theory uses more fine-tuned data and variables, it can provide more accurate and less biased predictions and explanations of internal migration patterns than macroeconomic theories.

Should we use Macro or Micro theories to describe internal migration?

Using microbehavioral theory, we can better understand internal migration in the US to and from the West Coast. While a macroeconomic theory would insist that there is net migration to the West Coast due to a high-wage, high-demand market, microbehavioral theory shows the more complex dynamics taking place.

The West Coast has many pull factors, which do include high wages, but which also include type of job market, physical and political environments, culture, growing tech industries, and company culture. However, there are many push factors as well, such as housing costs, environment (droughts, wildfires), politics, population, traffic, culture, and types of jobs.

There is considerable overlap in push and pull factors since people perceive aspects of an area very differently. Employment and high wages may not be the leading influencers for internal migration to the West Coast; culture and access to the ocean/sunny environment might be a primary reason for people.

Controlling for education level, gender, race, and age would produce many interesting results as well. We could get a better understanding if high wages on the West Coast are correlated with higher education, for example. Although it is generally assumed that more education is connected to higher wages, this is not always the case for the tech industry. Following microbehavioral theory, census data and select qualitative data could be used to understand the impact of education and pull of the physical environment for internal migration to the West Coast. Various push factors could also be studied in tandem with pull factors for the location migrants moved to.

Want to learn more?

Newbold, K. B. (2021). Chapter 6: Internal Migration. In Population geography: Tools and issues (pp. 129–154). essay, Rowman & Littlefield.

Newbold, K. B. (2021). Chapter 7: International Migration Flows – Immigrants and Transnational Migrants. In Population geography: Tools and issues (pp. 155–184). essay, Rowman & Littlefield.