Of course it is recognized in China, because you are a student of Columbia University anyway. STEM is a list of science and engineering, enjoying 29 months of OPT, while other majors only have 12 months of OPT, and STEM may have a little priority in applying for H1B. It seems that actuarial science is not. You'd better go to Google and search the list of STEM to see if actuarial science is on it. Forget the green card. Stay in America for at least eight or nine years. . . This is the fastest speed, or marry a ghost. . .