How can the world adequately feed more than 9 billion people by 2050 in a manner that advances economic development and reduces pressure on the environment? This is one of the paramount questions the world faces over the next four decades. Answering it requires a "great balancing act" of three needs -- each of which must be simultaneously met. First, the world needs to close the gap between the food available today and that needed by 2050. Second, the world needs agriculture to contribute to inclusive economic and social development. Third, the world needs to reduce agriculture's impact on the environment. The forthcoming 2013-14 World Resources Report, Creating a Sustainable Food Future, seeks to answer this question by proposing a menu of solutions that can achieve the great balancing act. "Achieving Replacement Level Fertility" profiles one of these solutions or "menu items," and is an installment in a series of working papers leading up to the World Resources Report. Since the 1980s, the World Resources Report has provided decisionmakers from government, business, and civil society with analyses and insights on major issues at the nexus of development and the environment. For more information about the World Resources Report and to access previous installments and editions, visit www.worldresourcesreport.org