They don&#x27;t, at least in the USA. My Ph.d. is from Texas at Austin, which is a public institution. During my time as a grad student I had numerous opportunities to &#x27;see how the sausage is made&#x27;. Even as a public institution the vast majority of funding (over 80% in the sciences) came from outside grants, such as federal agencies. A professors appointment is also only for 8 months of the year, and they must find outside funding sources to cover the other time.<p>This is the business model in each department, and it is why promotion to tenure is so focused on publications and grants.