Identifying causality in public institutional change: The adaptation of the National Assembly for Wales to the European Union

The aim of this article is to identify causes and effects of public institutional change. Analysis is centred on those endogenous, not exogenous, sources of political change that account for the institutional metamorphosis of the Welsh Assembly in its engagement with UK-EU processes since 1999. The central research question addressed is to explain a qualitative shift in the logic of action of Assembly engagement, resulting in the conduct of a territorially sensitive ‘parliamentary’ EU scrutiny, but within a model of executive devolution. To capture agency and change, and to engage with sociological institutionalist debates, the article develops analytical tools of ‘framing’ and ‘operationalizing’ institutions to study the interplay between informal and formal processes of institution building since devolution. In so doing, we place refined sociological conceptions of institutions at the heart of analyses of political discontinuity and theorization of public institutional change.