Australia’s modern economic development has received significant contributions from both migrants and foreign direct investment (FDI), with or despite migration and FDI policies following contrasting paths and being independently formulated. Using purpose-built quantitative policy indicators capturing the post-war period, two related papers examine the relationships between migration and FDI policies, flows and economic outcomes. The results evidence bidirectional flow complementarity that has increased with policies preferencing a more skilled, diverse and temporary migrant intake, but with mixed economic outcomes. Independent policy formulation has not appeared to maximise complementarity, with migration policy liberalisation biased towards incumbent firms deterring new foreign investors.