3 ms·

While interesting... is there no commentary or discussion about the causation? Thanks for posting the graph, but I'd be very curious why people think this has h

• serge2k 12y ago
  They do point out that since 2007 you need to have a passport to enter the states via air.
• esrauch 12y ago
  Since 2009 Canada started requiring a passport from everyone, even for land travel from the US (before that they accepted drivers licenses in some conditions, still accept "enhanced drivers licenses" in some cases)
• IvyMike 12y ago
  My theory: during the cold war, there was "America is the best" propaganda which even though it was really anti-Soviet, ended up discouraging people from travelling anywhere. Berlin wall fell in 1989, the cold war propaganda tapered off, and travel to foreign countries slowly ramped up.
  • brandonmenc 12y ago
    Doubtful. Cheaper airfare and people starting families much later (easier to travel when you're a single adult) are more likely factors.
  • IvyMike 12y ago
    May I ask why the downvote? My speculation may or may not be correct, but despite @brandonmenc's objection, I still think it's a possible factor. It certainly matches the attitudes of my relatives and other adults when I was a child growing up in the 80's. It's also more closely tied to the start of the trend line than some of the other theories in this thread, and was posted as a good faith response to @cguess.
• philwelch 12y ago
  After 9/11, the U.S. started requiring a passport to reenter the country, even from Canada or Mexico.