For a very long time I was a typical urban-educated upper-caste twit who balked at the idea of Reservations (or was I just being what the economists call a Rational Individual?). Some time in the last decade I became convinced that in a massively unbalanced society like ours equity can only restored with the helping hand of affirmative action. I won't go into the details of why I reached that conclusion, but I am a supporter of reservations, although I have huge issues with how it is being implemented; I'd prefer it to be timebound, statistics-based and more importanly executed on economic rather than religious lines. However, we are where we are and in order to get to the claimed objectives, we should be able to measure what percentage of a particular caste benefits from the opportunity handed out to them. We need to compare the stats across castes, states and over time to evaluate the efficacy of this scheme . For all this it's important to document the numbers and I can't think of a better way than through that mammoth data-collection activity that we already indulge in. While a caste-based census carries the risk of perpetuating divisions in society, not collecting numbers is bound to lead to massive abuse and a total lack of accountability.
Having said that what really gets my goat is that I can't mark my religion as "none" on the census form.