system
Given the following post, respond as if you're commenting on Reddit:
human
Difference between PhD degrees from different countries in the world?

A PhD degree in North America takes 6-7 years, in Europe it takes 3-4 years, in Asia and Africa it takes 5-6 years, no idea how long Australian and South American PhDs take. What is the difference between these PhDs? Would you prefer one of these over the others?
gpt
One major difference is that many American Ph.D. programs, especially in the sciences, functionally have a Master's program rolled in, whereas similar programs in other countries frequently expect students to complete a Master's before applying.