Research on economization processes is increasingly taking seriously the social and material processes through which various policy domains are transformed into economic problems and solutions. This article engages “Value Added Modeling” (VAM) in teacher evaluation systems as a case study in economization. VAM is a statistical technology for evaluating the effectiveness of schoolteachers using student test scores, which wrests authority for the determination of quality teaching away from education professionals and toward quantitative economic modelers. Mobilizing field theory, we trace a (...) half century of changing relationships among economists, other academics, and various policy audiences (from media to philanthropists to state and federal government) in struggles to define education policy concerning teacher quality. We show that economization is a set of overlapping, sometimes contradictory processes that can take different forms: in this case, the spread of an “economic style of reasoning” or the establishment of “economic policy devices.” The case of VAM shows stages of economization in which processes first proceeded independently of one another, then interacted in contradictory ways, and finally, mutually reinforced one another. What primarily drove these interactions was the struggle for scientific capital within the economics discipline and the changing place of education policy and VAM within it. Ultimately, VAM’s original role as a policy device for evaluating and selecting individual teachers has foundered even as it has become an important tool for economists to accrue scientific capital and expand their style of reasoning to broader audiences. (shrink)