This paper defends the viability of de-idealization strategies in economic modeling against recent criticism. De-idealization occurs when an idealized assumption of a theoretical model is replaced with a more realistic one. Recently, some scholars have raised objections against the possibility or fruitfulness of de-idealizing economic models, suggesting that economists do not employ this kind of strategy. We present a detailed case study from the theory of industrial organization, discussing three different models, two of which can be construed as de-idealized versions (...) of the first. We conclude that recent pessimism about de-idealization in economics is largely unfounded, and that de-idealization strategies are not only possible but also widely employed in economics. (shrink)

This paper contributes to the philosophical accounts of generalisation in formal modelling by introducing a conceptual framework that allows for recognising generalisations that are epistemically beneficial in the sense of contributing to the truth of a model result or component. The framework is useful for modellers themselves because it is shown how to recognise different kinds of generalisation on the basis of changes in model descriptions. Since epistemically beneficial generalisations usually de-idealise the model, the paper proposes a reformulation of the (...) well-known distinction between abstraction and idealisation. A reformulated notion of abstraction is needed because the extant accounts yield wrong judgments when model-modifications introduce implicit assumptions. (shrink)

This paper defends the viability of de-idealization strategies in economic modeling against recent criticism. De-idealization occurs when an idealized assumption of a theoretical model is replaced with a more realistic one. Recently, some scholars have raised objections against the possibility or fruitfulness of de-idealizing economic models, suggesting that economists do not employ this kind of strategy. We present a detailed case study from the theory of industrial organization, discussing three different models, two of which can be construed as de-idealized versions (...) of the first (the so-called Bertrand model of oligopoly). We conclude that recent pessimism about de-idealization in economics is largely unfounded, and that de-idealization strategies are not only possible but also widely employed in economics. (shrink)

The paper deals with the methodological clash between idealism and anti-idealism in political philosophy, and highlights its importance for public reason (PR) and public justification (PJ) theorising. Upon reviewing the broader context which harks back to Rawls’s notion of a realistic utopia, we focus on two major recent contributions to the debate in the work of David Estlund (the prototypical utopian) and Gerald Gaus (the cautious anti-utopian). While Estlund presents a powerful case on behalf of ideal theorising, claiming that motivational (...) incapacity and other non-ideal features of “human nature” – the so-called bad facts – do not normally refute the desirability of highly utopian theories of justice, we show that Gaus is correct in stressing the importance of feasibility considerations, including empirical knowledge about human societies. Because moral disagreement is to be expected even among cognitively and morally excellent reasoners, we argue that Estlund’s search for Truth about justice must idealise away normative diversity as just another bad fact. This methodological dispute has important ramifications for current debates about PR and PJ as the grounds of liberal legitimacy. Because consensual approaches rely on strong idealisation which results in exclusion of numerous comprehensive doctrines from consideration, we conclude that convergence-based liberal political theory has distinct advantage as regards exploiting normative diversity to the advantage of everyone. (shrink)