Search

Begin New Search Topic Economic Theory Author Roman Frydman

1. The Knightian Uncertainty Hypothesis: Unforeseeable Change and Muth’s Consistency Constraint in Modeling Aggregate Outcomes

Author:
Roman Frydman, Søren Johansen, Anders Rahbek, and Morten Tabor
Publication Date:
03-2019
Content Type:
Working Paper
Institution:
Institute for New Economic Thinking (INET)
Abstract:
This paper introduces the Knightian Uncertainty Hypothesis (KUH), a new approach to macroeconomics and finance theory. KUH rests on a novel mathematical framework that characterizes both measurable and Knightian uncertainty about economic outcomes. Relying on this framework and John Muth’s pathbreaking hypothesis, KUH represents participants’ forecasts to be consistent with both uncertainties. KUH thus enables models of aggregate outcomes that 1) are premised on market participants’ rationality, and 2) yet accord a role to both fundamental and psychological (and other non-fundamental) factors in driving outcomes. The paper also suggests how a KUH model’s quantitative predictions can be confronted with time-series data.
Topic:
Economics, Markets, Economic Theory, Macroeconomics, and Mathematics
Political Geography:
United States

2. Stock-Market Expectations: Econometric Evidence that both REH and Behavioral Insights Matter

Author:
Roman Frydman and Josh Stillwagon
Publication Date:
06-2016
Content Type:
Working Paper
Institution:
Institute for New Economic Thinking (INET)
Abstract:
Behavioral finance views stock-market investors’ expectations as largely unrelated to fundamental factors. Relying on survey data, this paper presents econometric evidence that fundamentals are a major driver of investors’ expectations. Although expectations are also in part extrapolative, this effect is transient. The paper’s approach underscores the central importance of opening models to structural change and imposing discipline on econometric analysis through specification testing. Our findings support the novel hypothesis that rational market participants, faced with unforeseeable change, base their forecasts on both fundamentals - the focus of the REH approach - and the psychological and technical considerations underlying behavioral finance.
Topic:
Markets, Economic Theory, Survey, and Stock Markets
Political Geography:
Global Focus