Book excerpt: Anyone who’s ever given up on a New Year’s resolution knows: Willpower eventually runs out. Whether the goal is personal or professional, the factor that really determines success is an individual’s commitment level. Heidi Reeder, PhD, is a highly regarded communication expert with a slew of high-level clients. In Commit to Win, she unpacks forty years of research by psychologists and economists to show how commitment boils down to just four variables: Treasures, Troubles, Contributions, and Choices. Showing how to harness these elements—and providing practical examples and action plans—Reeder gives everyone the tools to stop wishing—and start achieving.