Dervala.net: "I Was A Nonresident Alien":

The United States and Canada differ greatly in their treatment of skilled workers. Philosphically, Canada decides that these are good people to have around. They are a terrific deal for the country, after all: already vaccinated and highly-educated by foreign taxpayers, and ready to fill jobs where local skills fall short. They bring immigrant energy, and may even create jobs. Once an applicant qualifies on the stringent entry requirements, therefore, Canada grants freedom of labor movement and, after three years or so, full citizenship rights.

The United States, on the other hand, treats skilled workers like high-class indentured servants...