Interesting question but it really varies. There are advantages from a green card perspective to starting your own company because the successes of the company

Interesting question but it really varies. There are advantages from a green card perspective to starting your own company because the successes of the company can be attributed to you. That being said, the esteem of getting a PhD or doing a post-doc at a prestigious institution also helps. My general feeling about all this is not to let immigration drive these decisions because immigration usually takes care of itself if one does what one loves and wants to do. This is a general statement but I rarely see a positive outcome when one defers making a decision, whether to start a company or change jobs, because of immigration considerations.