India, March 18 -- The idea of a "social unicorn" has gained currency in India over the last few years. It reflects a collective ambition to build organisations that do not just demonstrate impact at the margins, but operate at population scale, shaping outcomes for hundreds of millions and eventually a billion people. Yet much of the conversation still assumes that these organisations will resemble either successful startups or scaled non-profits, only bigger. That assumption may be holding us back.

If India does produce social unicorns in the coming decade, and there are promising indicators to that end, many of them are likely to emerge from what's currently seen as an uncomfortable hybrid. They will sit between commercial markets and...