For the sake of comparison, the 25 million at Berkeley is less than one percent of that institution's total budget, but it's still 25 million dollars. To do what exactly? THAT is the great unknown. You get a lot of qualitative statements on the relative value or lack thereof with this spending, but not much in terms of quantitative effects.
This is a tough one and here are three examples of attempts to figure it out. At UC Berkeley, it is an enterprise that employs about 400 people: https://www.thecentersquare.com/california/uc-berkeley-spends-25m-a-year-pays-400-employees-to-advance-equity-and-inclusion/article_65d5a4ec-9894-11eb-b349-4324d0736e41.html
This is an attempt at more far-reaching data, including an attempt to figure out where the money goes: https://cspicenter.org/blog/cspi/the-black-hole-of-dei-spending-at-public-universities/
And there is this, which reads more like an advocacy piece than actual scholarship: https://www.insightintodiversity.com/an-insight-investigation-accounting-for-just-0-5-of-higher-educations-budgets-even-minimal-diversity-funding-supports-their-bottom-line/#:~:text=DEI%20spending%20often%20accounts%20for,four%2Dyear%20public%20institutions%2C%20according
For the sake of comparison, the 25 million at Berkeley is less than one percent of that institution's total budget, but it's still 25 million dollars. To do what exactly? THAT is the great unknown. You get a lot of qualitative statements on the relative value or lack thereof with this spending, but not much in terms of quantitative effects.