Thank you for this important question.
First of all, any sort of systemic racism or bias within any government operation is completely unacceptable. The results of that Pollara study are deeply concerning to me. They were the result of a proactive exercise from the department to figure out whether there was internal discrimination, and we're doing what we can to root out racism within the department—not just internal to the department, but as the effect of our policies, which is what your question touches on.
When I learned of this issue, I was quite concerned, but I've received an answer that is satisfactory to me. In Nigeria, the higher threshold is actually a lower total than students from other nations are required to provide. Though it's $10,000, they also need to make good on proof of funds for the cost of their tuition, the average of which—my officials can correct me if I'm off—is a total of $43,000. However, the issue is that we don't necessarily have financial partners on the ground in Nigeria, so having the proof of funds of $30,000 is more equitable when you look across the requirements in other countries, where you have not only $10,000, but also the proof of funds to cover the cost of an international student's tuition.
I looked into this when I learned about it, because I was quite concerned, but I saw that it wasn't quite the problem that I thought it was when I first learned of the details.