The economics of radical uncertainty

Paul Ormerod ()

No 2015-40, Economics Discussion Papers from Kiel Institute for the World Economy (IfW Kiel)

Abstract: In situations of what we now describe as radical uncertainty, the core model of agent behaviour, of rational autonomous agents with stable preferences, is not useful. Instead, a different principle, in which the decisions of an agent are based directly on the decisions and strategies of other agents, becomes the relevant core model. Preferences are not stable, but evolve. It is not a special case in such circumstances, but the general one. The author provides empirical evidence to suggest that as a description of behaviour in the modern world, economic rationality is applicable in a declining number of situations. He discusses models drawn from the modern literature on cultural evolution in which imitation of others is the basic strategy, and suggests a heuristic way of classifying situations in which the different models are relevant. The key point is that in situations where radical uncertainty is present, we require theoretical 'null' models of agent behaviour which are different from those of economic rationality. Under uncertainty, fundamentally different behavioural rules are 'rational'. The author gives an example of a very simple pure sentiment model of the business cycle, in which agents use very simple heuristic decision rules. It is nevertheless capable of approximating a number of deep features of output growth over the cycle.

Keywords: uncertainty; imitation; evolution; agent-based model; sentiment; business cycle (search for similar items in EconPapers)
JEL-codes: D81 E14 E32 (search for similar items in EconPapers)
Date: 2015
New Economics Papers: this item is included in nep-cbe, nep-cmp, nep-evo, nep-hme, nep-hpe, nep-mac and nep-pke
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.economics-ejournal.org/economics/discussionpapers/2015-40
https://www.econstor.eu/bitstream/10419/110918/1/827394306.pdf (application/pdf)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:zbw:ifwedp:201540

Access Statistics for this paper

More papers in Economics Discussion Papers from Kiel Institute for the World Economy (IfW Kiel) Contact information at EDIRC.
Bibliographic data for series maintained by ZBW - Leibniz Information Centre for Economics ().