Categories All the Way Down Marion Fourcade & Kieran Healy ∗ Abstract: »Kategorien auf der ganzen Linie«. Scores and classifications are dual to one another. Cardinal and ordinal measures are repeatedly used to produce nominal classifications of essential worth. Conversely, presumptively natural kinds provide the basis for new measurement and scoring systems. Over time, the iterative application of nominal classifications and quantifying measures produce involuted, nested systems whose structure and origins are hard to dis- entangle. While careful studies of earlier systems and methods have often un- covered these arbitrary aspects, newer technical tools for classification are at once substantially more opaque than their predecessors and more likely to be employed on very large scales. The classification situations to which they give rise thus have the potential to produce the sort of naturalized facticity charac- teristic of classical social facts. Keywords: Market classifications, scores, categories, classification situations, market sociology. The articles in this HSR Special Issue “Market Classifications” explore scoring and classification tools across a range of economic settings, and from a variety of perspectives. The settings range from the German wine market (Diaz-Bone 2017) to the American subprime credit sector (Rona-Tas 2017), from the sus- tainability and social investment sector to the British fashion world (Nagel et al. 2017; Schiller-Merkens 2017; all in this issue). The perspectives taken vari- ously see scoring and classification methods as tools for solving coordination or action problems in markets, as means for establishing and maintaining iden- tities (Pridmore and Hamalainen 2017, this issue) and as portable judgment devices with the capacity to be put to use beyond their original context (Chia- pello and Godefroy 2017, this issue). Across the contributions is the sense that, as Citron and Pasquale (2014) have suggested, we now live in “scored socie- ties” where increasingly large tracts of social life are subject to these methods, and in an increasingly automated manner. Discussing the credit crisis of 2007-08, MacKenzie (2011, 1830) asks “Should we understand the conduct of those practices and the use of their results as having been driven by belief in them, or should it be seen as cynical, as driven simply by the pursuit of gain (e.g., by Marion Fourcade, Department of Sociology, University of California, Berkeley, CA 94720- 1980, USA; fourcade@berkeley.edu. Kieran Healy, Department of Sociology, Duke University, Durham, NC 27708, USA; kjhealy@soc.duke.edu. Historical Social Research 42 (2017) 1, 286-296 Ň© GESIS DOI: 10.12759/hsr.42.2017.1.286-296