If a problem is political providing proof might be very difficult, since those in power will claim that there is no proof of a problem existing, and hence there is no need to investigate the problem further. This circular logic prevents any kind of proof from ever being produced.
I've seen this happen many times myself.
Kamaal made a claim that "stories of having scored in upwards of 95% aggregate marks, and best rank in competitive exams(JEE, NEET, NATA, CET etc) and lose out an engineering seat to some one who had 35-45% marks."
This is what I have seen too. And yet, I cannot provide any citations because the agencies and the institutions do not publish figures. Saimiam knows this, and himself cannot produce figures of any sort in this field. Our governmental agencies make policies not based on research and citations, but based on what gets them most votes. The govermnent has no incentive to fund research in the field.
This gives a nice cover for people to hide behind, and say, "No proof. Ha ha."
This topic is very measurable, regardless of the government's stance. The government cannot prevent proof of this. At most they can just not fund it.
Providing proof may then become prohibitively expensive, and sometimes impossible.
Even in the US, a lot of data is not released on the grounds of confidentiality. That doesn't block doing research on the topic.