This paper examines the impact of aid on economic growth using cross-sectional and panel data, addressing potential endogeneity issues. The authors correct for the bias that poorer or stronger growth may attract more aid, but find little robust evidence of a positive or negative relationship between aid inflows and economic growth. They also find no evidence that aid works better in better policy or geographical environments, or that certain forms of aid are more effective than others. The findings suggest that for aid to be effective, the aid apparatus will need to be rethought. The paper uses a comprehensive framework to analyze the aid-growth relationship, examining various time horizons, sources of aid, types of aid, and geographical settings. The authors construct instruments for aid based on donor-related characteristics, such as historical relationships and influence, to address endogeneity. The results are consistent across different specifications and samples, indicating that the effects of aid on growth are likely too small to detect against the background noise. The paper concludes by discussing the implications for aid policies and the need for further research to improve aid effectiveness.This paper examines the impact of aid on economic growth using cross-sectional and panel data, addressing potential endogeneity issues. The authors correct for the bias that poorer or stronger growth may attract more aid, but find little robust evidence of a positive or negative relationship between aid inflows and economic growth. They also find no evidence that aid works better in better policy or geographical environments, or that certain forms of aid are more effective than others. The findings suggest that for aid to be effective, the aid apparatus will need to be rethought. The paper uses a comprehensive framework to analyze the aid-growth relationship, examining various time horizons, sources of aid, types of aid, and geographical settings. The authors construct instruments for aid based on donor-related characteristics, such as historical relationships and influence, to address endogeneity. The results are consistent across different specifications and samples, indicating that the effects of aid on growth are likely too small to detect against the background noise. The paper concludes by discussing the implications for aid policies and the need for further research to improve aid effectiveness.