“What do museums do when they lose an old master? If it’s a painting they call the police. If it’s an esteemed leader, they call Malcolm MacKay.” MacKay is an executive headhunter specializing in museums, and has become arguably the most powerful man in the business in recent years. Last year alone, he led five searches for major American museum executives, and he was the first person the Art Institute of Chicago called last year when longtime director James Wood announced his retirement. Not a bad track record for a Harvard lawyer with no academic experience in art.