To those of us fortunate to know him, CK Prahalad's death is both unexpected and a huge personal loss. He was so vital, so full of creative energy, that it seems hard to believe he is not still here, brimming with new ideas, backed by a diagram and compelling anecdote.

CK was a gifted teacher, a prolific author, and a consummate strategy consultant, best known to the corporate world for his work on core competence. But for the NextBillion audience, he is simply the founder (with Stu Hart) of the Base of the Pyramid concept - that business approaches could be harnessed to address poverty, that low income markets could yield not only profits and improved opportunity for the poor but also fundamental innovations for the world at large. 

He was also a warm personal friend to many, a generous mentor to generations of students, and devoted to his family. For me personally, he was the catalyst for - and often partner in - much of my work over the past decade. We will miss his vision, his ability to think outside conventional frameworks, and his unfailing kindness.