Keynesian expectations, epistemic authority and pluralism in economics: placebo and nocebo effects in normal and abnormal times.

This article examines how prominent economists, regarded as possessing epistemic authority—the public's inclination to treat their opinions as definitive evidence—may influence economic expectations in ways that produce self-fulfilling "placebo" or "nocebo" effects, whereby widely and confidently held expert forecasts encourage behaviors that help realize the predicted economic outcomes. It argues that the marginal status of pluralism within the economics discipline supports these dynamics by fostering a clear hierarchy of experts, promoting convergence in economists' expectational guidance, and facilitating its dissemination through intermediaries such as media and policymakers. Drawing on Keynesian theory of conventional expectations and lay epistemology, the article highlights that these self-fulfilling effects depend on contingent conditions, including public trust in economists' authority and the coherence of their forecasts, which may be undermined during "abnormal times" of economic instability. The conclusion considers how such crises might discredit economists' epistemic authority, potentially opening space for greater disciplinary pluralism or alternative sources of expectational guidance.