Radical Uncertainty and Economic Decision-Making: Revisiting Prediction, Forecasting, and South Africa's Policy Uncertainty Index

South Africa's growth performance over the past decade has unfold- ed in what Kay and King describe as an era of radical uncertainty, where the future is not merely unknown but unknowable. This article addresses how policymakers and businesses should interpret and use uncertainty indicators in such a context. We analyse the behaviour of the Policy Uncertainty Index (PUI) from its inception in 2016 to 2024, benchmarking it against the World Uncertainty Index and the BER Business Confidence Index. The evidence shows that South Africa's uncertainty is shaped both by global disruptions and by idiosyncratic domestic shocks associated with state capture, policy reversals and infrastructure failure. Persistent, elevated PUI readings are accompanied by weak confidence, record corporate cash holdings and a chronically low investment-to-GDP ratio, suggest- ing that policy uncertainty operates like a risk premium on doing business and discourages fixed investment. The key contribution of the paper is to reframe the PUI as an interpretive compass for ori- entation, dialogue and stress-testing of policy scenarios, rather than as a tool for point forecasting. We argue that clear communication, credible institutions and robust, adaptable reforms are central to rebuilding confidence and navigating unavoidable uncertainty.