Just to clarify, this is a “yes, and” post, not a “yes, but” post.
Alternatively, UIUC became a CS powerhouse by investing heavily in CS. Having one of the supercomputing centers in the mid 1980s was also part of it, though their proposal would not have been selected had they not already invested heavily in CS. In many ways, UIUC is a CS powerhouse because of NCSA.
On that topic - PSC, another supercomputer center, was also likely part of CMU’s rise to prominence in CS. That was a huge investment from NSF. CMU also got the equivalent of $6 million in 1962 to establish a CS department, and the equivalent of $50 million in 1965.
It’s also good to remember that CMU also has a long history of funding by The R. K. Mellon Foundation - some $300,000 until now, and they have now established a partnership. They were the ones who provided the heavy support for established CS in CMU.
They also have the Dietrich foundation, another almost 1.5 billion, which also functions essentially, as an endowment, their relationship with the RK Mellon foundation, which provides more than the distributions they get from their endowment, and the funding that they can raise for projects like expanding CS.
So their endowment is not the whole story of their ability to fund CS.
However, you’re also right. In 1970/1971, they lost around half of their faculty, but two Turing awards in 1975 and a Nobel in 1978 probably did a lot to start bringing more people in.
So funding is required for established a “prestigious” department in most cases, but it’s not enough. The department has to also be run in a manner which foster work that generates interest in the field. There are many stories of well-funded assorted initiatives in academia which amounted to little because they were run badly. For example, departments which get a chunk of money, go on a hiring spree, but neglect to provide the new faculty with the resources (equipment, graduate student assistantships, etc) that the faculty, both new and established, need to succeed.
I’m just pointing out the importance of funding or other benefits which both bring the initial “star” faculty and support their research, and which help draw faculty from other places which may not provide as much research support.
All of that being said, it’s also good to remember that academics have sizable egos, which can sometimes make building a good department which includes a number of “stars”, more challenging. Having a extensive resources can mitigate some of those challenges.
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Another factor that’s attractive for faculty, especially those who are not yet full professors, is having a program which is attractive for grad students. Having good grad students is essential for having a good and productive lab. That means both resources (to support grad students), but, often more important, especially these days, are other types of support, as well as having an overall culture which is not toxic.
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