Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
GDP is measured with error. But data uncertainty is rarely communicated quantitatively in real‐time. An exception are the fan charts for historical real GDP growth published by the Bank of England. To assess how well data uncertainty is understood, we first evaluate the accuracy of the historical fan charts. We find that data uncertainties can be accurately quantified, even without judgement, using past revisions data. Secondly, we conduct an online survey to gauge perceptions of GDP data uncertainty across a wider set of experts. Our results call for greater communication of data uncertainties to anchor experts' dispersed expectations.