This is my personal homepage. Find my philosophical papers under "Philosophy".

The paper explores how, in economics and biology, theoretical models are used as explanatory devices. It focuses on a modelling strategy by which, instead of starting with an unexplained regularity in the world, the modeller begins by creating a credible model world. The model world exhibits a regularity, induced by a mechanism in that world. The modeller concludes that there may be a part of the real world in which a similar regularity occurs and that, were that the case, the (...) model would offer an explanation. Little concrete guidance is given about where such a regularity might be found. Three modelling exercises in evolutionary game theory—one from economics and two from biology—are used as case studies. Two of these (one from each discipline) exemplify ‘explanation in search of observation’. The third goes a step further, analysing a regularity in a model world and treating it as informative about the real world, but without saying anything about real phenomena. The paper argues that if the relation between the model and real worlds is understood in terms of similarity, and if modelling is understood as an ongoing discovery process rather than as the demonstration of empirical truths, there can be value in creating explanations before finding the regularities that are to be explained. (shrink)

Policy-makers face an uncertain world. One way of getting a handle on decision-making in such an environment is to rely on evidence. Despite the recent increase in post-fact figures in politics, evidence-based policymaking takes centre stage in policy-setting institutions. Often, however, policy-makers face large volumes of evidence from different sources. Robustness analysis can, prima facie, handle this evidential diversity. Roughly, a hypothesis is supported by robust evidence if the different evidential sources are in agreement. In this thesis, I strengthen the (...) case for the use of robustness analysis in evidence-based policymaking by answering open research questions about this inference technique. First, I argue that existing taxonomies miss a fruitful category of robustness reasoning, that is predictive stability. Second, I claim that derivational robustness analysis – the investigation of whether the results of different models are in agreement – can yield interesting insights even if not the entire relevant model space is covered by available models or if the model results are only partially in agreement. Third, I claim that expert knowledge is necessary to address questions that arise when one applies measurement robustness analysis – the investigation into whether multiple means of measurement yield the same result. Finally, I argue that, in situations where evidence from different measurements is not in agreement, it can be advisable to no longer take all of the evidence into account. This can be done in a rationally defensible way by choosing the most adequate theory or model underlying parts of the evidence set. I discuss examples from climate, medical, and economic policy-making to establish my claims. (shrink)

This essay examines the issue of false assumptions in models via a case study of a prominent economic model of sustainable development, wherein the assumption of an infinite future plays a central role. Two proposals are found to be helpful for this case, one based on the concept of derivational robustness and the other on understanding. Both suggest that the assumption of an infinite future, while arguably legitimate in some applications of the model, is problematic with respect to what I (...) call “Parfitian” welfare functions. This result is relevant to debates about discounting the future in economics and environmental ethics. (shrink)

How is it possible that models from game theory, which are typically highly idealised, can be harnessed for designing institutions through which we interact? I argue that game theory assumes that social interactions have a specific structure, which is uncovered with the help of directed graphs. The graphs make explicit how game theory encodes counterfactual information in natural collections of its models and can therefore be used to track how model-interventions change model-outcomes. For model-interventions to inform real-world design requires the (...) truth of a causal hypothesis, namely that structural relations specified in a model approximate causal relations in the target interaction; or in other words, that the directed graph can be interpreted causally. In order to increase their confidence in this hypothesis, market designers complement their models with natural and laboratory experiments, and computational methods. Throughout the paper, the reform of a matching market for medical residents provides a case study for my proposed view, which hasn't been previously considered in the philosophy of science. (shrink)

RESUMEN: En el presente trabajo se hará una crítica al enfoque de máquinas nomológicas desarrollado por Nancy Cartwright para el caso de las ciencias sociales. Se argumentará que los fenómenos sociales no responden a una lógica de "capacidades", sino de "árboles de posibilidades" o "resultados de final abierto". La estabilidad o invarianza, si bien es posible en el reino de lo social, parece ser más la excepción que la regla. Esto tiene consecuencias importantes para los propósitos de intervención y control. (...) De acuerdo con las corrientes manipulabilistas tradicionales la invarianza es una herramienta fundamental para cumplir cualquier propósito intervencionista, ya que permite prever con un buen grado de confianza el resultado de una manipulación. Sin embargo, en este trabajo se intentará mostrar que, a pesar de que no sea del todo plausible obtener un conocimiento invariante en el reino de lo social, las intervenciones pueden ser igualmente eficaces. Para ello, será fundamental reemplazar la noción "ex-ante" de intervención por una que involucre continuidad o sistematicidad. También será clave tener en cuenta aquellas cláusulas o condiciones especificadas dentro de los modelos, ya que estos últimos cumplen el rol de ser anteproyectos para la generación de resultados. ABSTRACT: In the present paper, a critique of Nancy Cartwright's nomological machines approach in the social sciences will be made. It is argued that social phenomena do not correspond to the logic of "capacities", but to the logic of "possibility trees" or "open-ended results". Stability or invariance, although possible in the social realm, seem to be more the exception than the rule. This has important implications for the purposes of intervention and control. According to traditional manipulabilistic accounts, invariance is essential for achieving any interventionist purpose, because it allows predicting the result of a manipulation with a high degree of confidence. However, in this paper it will be shown that even though the obtaining of invariant knowledge is not entirely plausible in the social realm, interventions may be effective. To do this, it will be necessary to replace the "ex-ante" notion of intervention with another notion that involves continuity. It will also be crucial to take into account the clauses or conditions specified in models, since such models play the role of being blueprints for generating results. (shrink)