After the recent pandemic lock down there has been a significant increase in air travel. 

I see several reasons for this movement.

The first was the popularity of college education in America.  (Table) The number of people going to college as measured by bachelor’s degrees tripled over thirty years going from 10% of the population in the 1970s to over 30% by 2000. Americans moved to new geographies after college, often the result of marriage to a college peer from a different locale.

The second was political divergence and social sorting by politics.  Beginning in the 1980s more people chose to live close to other people of their own political persuasion.  Several books have been written on this subject.

By 2000, the Internet was becoming a popular form of communication as was the cell phone with the subsequent disappearance of telephone distance charges. Friendships formed and survived geographic distances.

The final coup d’etat was a pandemic lockdown where nearly 70% of workers found they could work off-premise using the Internet and cell phones.

All four of these major social changes resulted in Americans and other global citizens finding reasons to travel, live in new locales, and feel comfortable doing it.