Measure Twice, Cut Once: Entrepreneurial Ecosystem Metrics

•We create a dataset to measure Entrepreneurial Ecosystems in 273 regions in Europe.•We show how the elements of Entrepreneurial Ecosystems are interdependent.•An Entrepreneurial Ecosystem Index is created to qualify entrepreneurial ecosystems.•The Index predicts entrepreneurial output better than other indices.•Entrepreneurial Ecosystem metrics enable data-and-dialogue-driven policy.