The Atlantic Canada Opportunities Agency (ACOA) was established in 1987 as the federal government agent for ecc development in Atlantic Canada. This article describes the Agency's "corporate" approach to provide credible, quantitative estimates of the long-term policy outcomes of total Agency activity. The focus of evaluation activity has been to determine the contribution of ACOA as a whole to its legislated mandate to enhance the growth of earned incomes and employment opportunities in Atlantic Canada. To provide reliable impact estimates for senior management, ministers, parliamentarians, stakeholders and taxpayers, the Agency has used multiple lines of evidence, both qualitative (client-user surveys and independent verifications) and quantitative, such as ecc statistics from multiple sources, ectric modelling, and time-trend analysis versus a comparison group (ACOA clients versus all Atlantic small- and medium-sized enterprises), to measure policy outcomes. This methodological approach is detailed and the findings with respect to broad macro-ecc indicators such as employment creation, earned income, tax revenues, and the unemployment rate are presented.