註釋 Over the last decade and a half, during a period defined in the public consciousness by political partisanship, the legislative and executive branches have quietly forged a bipartisan consensus around the need to build evidence of effectiveness that would ensure high rates of return on investment for the nation's social programs. The establishment by Congress of the new Evidence-Based Policymaking Commission is only the most recent example of this consensus. In this testimony Gordon L. Berlin, the President of Manpower Demonstration Research Corporation (MDRC), offers a brief history of the federal government's fruitful investment in evidence-building; then concentrates on several of the most recent efforts, including supporting pay-for-success initiatives; and concludes by identifying obstacles to effective evidence-building, offering potential solutions and suggesting a framework for exploiting the opportunities that lie ahead. 