The Eurozone Organization for Economic Co-operation and Development (OECD) Leading Indicator is an economic indicator that provides a composite measure of economic activity and predicts future economic activity in the Eurozone. The indicator is based on a variety of economic data, including business surveys, stock prices, and money supply figures. The Eurozone OECD Leading Indicator is considered a leading indicator because it provides insight into future economic activity, such as economic growth and inflation, before they are reflected in other economic indicators such as GDP.