Accepted Article Reconceptualizing Layering. From mode of institutional change to mode of institutional design: Types and outputs Giliberto CAPANO University of Bologna Department of Political and social Sciences giliberto.capano@unibo.it ABSTRACT Due to its popularity, the term layering is often used generically, and it risks being transformed into a catch-all concept. Layering has become synonymous with incremental change, thus making it a synonym for change without any specification in terms of the change and its effects. To make the term more conceptually coherent and empirically useful, this paper problematizes the historical neo-institutionalist definition of layering as a mode of change and, above all, its use in the literature. It argues that layering should be conceptualized in terms of modes of institutional design through which different types of additions to the actual institutional arrangement can be activated to pursue not only institutional and eventually policy change but also stability. As an approach to institutional design, layering can be distinguished according to that which is layered and the results that layering can achieve in terms of institutional and policy effects. 1. INTRODUCTION Layering is a popular concept among social scientists who focus their research on institutional and policy change. This concept was introduced by historical neo- institutionalism, which has defined layering as a specific mode of institutional change. However, against the initial conceptualization (or partially because of it, as I show This article is protected by copyright. All rights reserved. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/padm.12583