The NC-OBC reservation along with batch size increase in the IIMs has positively impacted the academic grades of both general merit students as well as reserved category students in the IIMs.
In the pre-OBC period, we had closer competition at the top in the IIMs with fewer marks separating over two-third of the section in both core courses and electives. With relative grading, this high bunching of marks at the top forced those who did marginally worse in any evaluation component into the B or C grades. With OBC reservation the competition at the top is now far lesser in the core courses and there is more uniform spread of marks. So only those who do badly very consistently over the course get into the C range and below. Even those who may not have done well in their first year now have scope to do better in their second year by choosing those electives where they can do better due to their natural ability and/or which have lesser competition. With less bunching of marks in the electives too their grade improvement chances are better. Moreover with a larger batch size more electives and more diverse electives are now running in the IIMs than earlier. Many good electives that could not run in earlier years due to low demand are now running due to the larger batch, giving all students a more diverse choice of electives than before. OBC reservation has thus been beneficial to both general merit students and reserved category admitted students.
To illustrate, in the pre-OBC reservation period IIM Bangalore had about 255 students (with distribution of Gen=190; SC=38; ST=19; PWD=8) and with-OBC reservation IIM Bangalore now has about 400 students (with distribution of Gen=190; OBC=108; SC=60; ST=30; PWD=12). So in the pre-OBC reservation period IIM Bangalore had four sections of 64 students each (Gen=48; SC=9; ST=5; PWD=2). With OBC reservation, IIM Bangalore now has six sections of 67 students each (Gen=32; OBC=18; SC=10; ST=5; PWD=2). IIM Bangalore has a relative grading system that has remained unchanged across the two periods (a maximum of 25% students can get an A grade and a maximum of 70% students can get an A+B grades).
Let us take a hypothetical core course in the first year PGP at IIM Bangalore where all the general merit students happened to score better than all students admitted under reservation – a seemingly reasonable (but not entirely true!) assumption. The table shows the grade distribution between general merit students and reserved category students in the pre-OBC and with-OBC periods under this assumption. In the pre-OBC period general merit students in a section would have had an average grade of 3.21 on 4 while reserved category students would have had an average grade of 1.97 on 4. With OBC reservation the general merit students in a section now have a higher average grade of 3.52 on 4 while the reserved category students also have a higher average grade of 2.32 on 4. This illustrative calculation shows that both general merit students as a group and the reserved category students as a group are better off after the NC-OBC reservation and the increase in seats.
Even if we relax the assumption that all general merit students will score better than all reserved category students, then these two averages will move closer to each other but even then both will still be better than in the pre-OBC period. This effect is primarily due to reduced competition now compared to the pre-OBC reservation years. Naturally this may have reduced grade orientation among students and may have had positive impact on job prospects of both general merit and reserved category students in companies that shortlist with a specific grade point average cutoff.
The view that OBC reservation has created “mediocrity” in the IIMs is biased and does not hold up to data. For example, the IIM Bangalore (check the RTI based report on insideiim.com) PGP class of 2013-15 General Merit vs OBC averages were 10th (92.75 vs 91.35), 12th (91.73 vs 91.19), graduation (87.61 vs 83.93). These OBC admits average prior academic scores are not “mediocre” and many of these OBC admits do better than the general merit admits. The Supreme Court has also ruled that the admission score of the last OBC candidate offered cannot be more than 10% lower than that of the last general candidate offered after which simultaneous offers are made down the waiting list to both general and OBC candidates to retain this 10% limit.
Interestingly in the PGP batch of 2012-14 where RTI data is available for both IIM Ahmedabad and IIM Bangalore (insideiim.com) the data shows that OBC admits at IIMB that year had slightly better 10th and 12th average scores than the General Merit admits at IIMA and had marginally lower (but by no means mediocre) graduation scores! General Merit admits at IIMA vs OBC admits at IIMB averages were 10th (90.40 vs 91.08), 12th (89.80 vs 90.13), graduation (85.29 vs 82.98). It is these three scores along with the CGPA at IIM that counts on the academic front for placements and CAT scores are irrelevant!