For those of you who are interested in this topic, here is an excellent article by Pranab Bardhan in today's NYT called "The Slowing of Two Economic Giants". Two excerpts:

But China’s rigid political system makes it heavily dependent on enlightened consensus among its nonelected rulers, while India’s ramshackle, pluralistic democracy has been surprisingly supple, even if its citizens haven’t reaped the material benefits yet. They share a fundamental problem — a lack of accountability, especially at the local level — that, if not addressed, will make it impossible to sustain strong economic growth and provide a social safety net. In India, democracy is weakest at the village level: electoral participation is vigorous, but local elites often capture the local government, leaving bureaucrats little autonomy (or money) to carry out substantial improvements. In China, the failure of accountability is national, and inherent in the authoritarian system.

In the medium term, I anticipate that the two countries’ rates of economic growth will converge in the not-too-distant future, as India reaps the benefits of having a younger population. But in the long run, which country does better will depend on political reform, or its absence.