There’s nothing that corporations and their executives worry about so often as the bottom line — it’s one metric their boards of directors and stockholders won’t let them forget. Most families, by contrast, don’t take such a business-like approach to their finances, their assets or their choices. Douglas McCormick, managing partner at MCI Equity Partners, wondered why not. More to the point, in his new book,  Family Inc.: Using Business Principles to Maximize Your Family’s Wealth, he explains just how much better off we all might be if we did. He joined the Knowledge at Wharton Show on Sirius XM channel 111 to talk about the biggest asset you probably have forgotten you own and how you can use it more wisely, and how to make family decisions based on long-term returns. An edited transcript of the interview follows.     Knowledge at Wharton: There are a lot of books out there that tackle what to do with family finances right now.…