The best person in the teaching market can get the position of assistant professor directly without doing blog posts.

The doctor has a graduation thesis, a defense and a graduation ceremony; Postdoctoral students have none of these. He didn't have to pass any exams and didn't finish the ceremony.

If you have completed the doctoral program, but failed to get a doctorate through defense, you can't call yourself a doctor on your resume, which is cheating. However, even if you quit after only one month, you can still put this month's postdoctoral experience on your resume. In principle, both the employer (school) and the employee (doctor) can terminate the contract. Don't worry about leaving early and not getting a postdoctoral fellow, because there is no postdoctoral fellow at all.

Basically, no one will get a doctorate in one school and then go to another school to study for a doctorate in the same major, because this behavior is meaningless. However, many people will change schools to become second-round postdoctoral fellows after the expiration of the first-round postdoctoral fellows. This is not because they like to collect doctoral titles from different schools, but because they can't find a formal teaching position, so they have to continue to be doctors and continue their academic career.

In the United States, the treatment of doctoral students is higher than that of doctoral scholarships, but not much. For example, the Ph.D. scholarship in mathematics at the University of Pennsylvania is now around 30,000 a year, and it is close to 60,000 after studying for a doctorate. However, the tax to be paid after the doctor is much higher than that of the doctor (PhD fellowship does not need to pay taxes, TA needs to pay taxes, I remember it seems to be more than 2,000 yuan a year, and the tax relief brought by the Sino-US tax exemption agreement has deducted the income of the first 5,000 yuan; I didn't specifically ask about the post-doctoral tax, which should be higher), and the deduction is not much more than the doctoral scholarship.