I have seen several questions pertaining to the salaries of professors in the United States. Is there any research/study/survey/... that looked at the non-salary income computer science academics (professors, research scientists, …) make in the United States?
By non-salary income I mean any income that doesn't come from the salary. Examples of income source: teaching outside the university, cash from awards, running a side start-up/business, consulting, sitting on boards of directors, giving talks, book royalties, patent royalties. Ideally, the non-salary income should be broken down by the income source.