Models and the locus of their truth

Abstract

If models can be true, where is their truth located? Giere (Explaining science, University of Chicago Press, Chicago, 1988) has suggested an account of theoretical models on which models themselves are not truth-valued. The paper suggests modifying Giere's account without going all the way to purely pragmatic conceptions of truth-while giving pragmatics a prominent role in modeling and truth-acquisition. The strategy of the paper is to ask: if I want to relocate truth inside models, how do I get it, what else do I need to accept and reject? In particular, what ideas about model and truth do I need? The case used as an illustration is the world's first economic model, that of von Thünen (1826/1842) on agricultural land use in the highly idealized Isolated State.

Reflections on the 2017 Nobel Memorial Prize Awarded to Richard Thaler

“…First, the concept is ambiguous. To say that an assumption is realistic might mean either (i) that it describes its target correctly in every aspect ('the-wholetruth' view), or (ii) that it describes at least some aspect correctly ('nothing-but-the-truth' view), or (iii) that it approximates all or some aspects of its target (Mäki 2011). This, secondly, drives a wedge between realisticness and truth.…”

“…A theory with unrealistic assumptions may be true, for example when it correctly describes some aspect of the target, even though some of its assumptions are considered unrealistic because they violates the-whole-truth view. For this reason, thirdly, realism (as a theory of theories) is perfectly comfortable with unrealistic assumptions, as has long been established by Cartwright (1989), and Mäki (2011). But then realisticness of assumptions by itself is not a good criterion for assessing models, nor is unrealisticness by itself a reason to reject a model.…”

Dani Rodrik's Economics rules: the rights and wrongs of the dismal science. New York: W. W. Norton & Company, 2015, 272 pp.

“…Rodrik believes that economists use the method of isolation (Mäki 1992;Mäki 2010) and echoes Mäki (2005) Thus, Rodrik contends that even though models misrepresent reality in many respects, they isolate real causal mechanisms. Or as he puts it "models are never true; but there is truth in models" (p. 44)-again echoing Uskali Mäki (2011). Rodrik takes it that isolating causal mechanisms and studying them (under the conditions specified by the model) helps economists in learning about "tendencies" and "likely consequences" (p. 45).…”

Modelos económicos: ¿representaciones aisladas o construcciones ficticias?

“…El enfoque de los modelos como aislamientos teoréticos presupone una ontología de factores causales estables como los mecanismos (Mäki, 1992(Mäki, , 2009(Mäki, , 2011 o las capacidades (Cartwright, 1998(Cartwright, , 1999a. Puesto que dichos mecanismos (supuestamente) existen en los sistemas socioeconómicos, el científico puede apelar a herramientas puramente teoréticas para obtener la contribución pura del factor bajo análisis.…”