Recorded 22 January 2024. Karel Martens of Technion - Israel Institute of Technology presents "Philosophy before mathematics: on equity principles and transport" at IPAM's Mathematical Foundations for Equity in Transportation Systems Workshop. Abstract: The development of mathematical foundations for equity in transportation systems requires a careful definition of what is meant by ‘equity’ before turning to the mathematical foundations. In my presentation, I aim to contribute in two ways to the discussion. First, I will provide a broad overview of how equity could be understood, drawing both on the philosophical literature and the civil rights discourse in the US. In the philosophical literature, equity or justice is often defined as the “morally proper distribution of benefits and burdens over members of society”. This distributive perspective thus highlights three key components of equity: (1) the benefits and burdens that are being distributed; (2) the populations and social groups over which they are distributed; and (3) the principle that determines whether or not a given distribution is considered “morally proper.” Jointly, these three dimensions generate a matrix of possible equity definitions, juxtaposing benefits and burdens like mobility, accessibility, health impacts and pollution, with moral principles like equality, proportionality, sufficiency, and equalization. More recently, a relational approach to justice has emerged and challenged the distributional perspective. This relational approach calls for a more fundamental reflection on the role of transport in society, not limiting that role to the benefits and burdens it generates, but asking how transport hinders or can contribute to “a world of equals”, which is seen as the fundamental attribute of, and prerequisite for, a just society. Second, I will reflect on the challenges of measuring equity even in case a general agreement exists on how to understand equity of transport systems. For this purpose, I will draw on my book Transport Justice. In the book, I argue that the equity of transport systems should be assessed based on the accessibility rather than the mobility it confers to people. Yet, measuring accessibility raises so many operational questions, that any empirical study of accessibility can be challenged on methodological grounds. The answer may paradoxically lie in a novel way to analyze mobility, even though in a philosophical sense mobility – people’s actual movement – is at best of secondary importance. I will illustrate the potential relevance of measuring mobility to understand equity by exploiting four GPS-based travel behavior surveys conducted in Israel (N = 60,971). The results show powerfully how a non-ideal metric can provide important insights into the equity of transport systems. Learn more online at: https://www.ipam.ucla.edu/programs/workshops/mathematical-foundations-for-equity-in-transportation-systems-january-22-26-2024/?tab=overview