The world is increasingly turning to its women for vision, talent, and leadership. When female leaders are present in significant numbers, the bottom line improves—from financial profits to the quality and scope of decision-making. Since most of us are open to and intent on bringing more women on board to help build a better world, why do we keep seeing a gender gap in leadership, with an average of only 18 percent of female leaders at the top of most professions? Studies show women are at least as capable as men, and that many are eager to lead. What is holding us back? In this all-women issue, we asked contributors how they became confident businesswomen and top earners in their companies.