How did IBM, General Electric and other companies become growth leaders? Why is it that some companies lag behind — and stay behind? Those are the questions that Wharton marketing professor George S. Day explores in his book, Innovation Prowess: Leadership Strategies for Accelerating Growth . Recently, Day spoke with David Heckman, practice leader, senior management at the Wharton School’s Aresty Institute of Executive Education , about why innovation prowess is the key to growth leadership. An edited transcript of the conversation follows. David Heckman: I’m here with professor George Day to interview him about his new book, Innovation Prowess . George, welcome to Knowledge at Wharton. George S. Day: Thank you, Dave. I’m very excited about sharing my thinking on my new book, Innovation Prowess . I’ve been working for over 25 years to understand what distinguishes consistent growth leaders — that is, companies that grow organically with their own resources — from growth laggards.…