Introduction: the value of historical perspectives Industrial districts have attracted increasing interest from scholars, policy makers, and the business community in recent years. While these socioeconomic^spatial phenomena appear to hold out an alluring promise of sustainable and equitable growth, several strands of research have argued that clustering is not always an unalloyed boon. In a recent special issue of Environment and Planning A, guest editors Hassink and Shin sought an advance in our understanding of the evolution of regions, clusters, and districts, and, in particular, of decline in mature systems. To that end, they and their contributors make the```lock-in' concept'', which they describe as``one of the few promising modern concepts'' with the potential to explain such phenomena, the``theoretical core'' of their programme (2005, page 571). At the same time, however, they also note the current weakness and fuzziness of the concept, resulting from its inductive origins and a lack of genuine comparative work. Chapman, in the same issue, suggests that a further cause of this weakness may stem from the fact that``much of the clusters discourse ... appears to lack historical perspective'' (2005, page 597). This seems surprising, however, given the sustained attention paid by economic and business historians to these issues (Wilson and Popp, 2003). In this paper we will present some of the fruits of that historical interest as they relate to the concerns central to the special issue.This common focus among the disciplines provides a strong justification for this paper. However, we also have reservations about aspects of the work conducted by geographers and presented in the special issue. These reservations hopefully provide the opportunity for a fruitful dialogue between economic geography and economic history. We will first outline some of our reservations before indicating the contribution that we believe a historical perspective can make to the lock-in concept and other, related debates within economic geography. As a statement of principle, we are concerned first and foremost with historical as well as with abstract time, with process, and with agency, defined as the extent to which actors are able both to make and to enact choices.Firstly, in terms of our response to the special issue, we have reservations about the presentation of the promising concept of contingency. Contingency in some of these studies appears as a form of deus ex machina that is exogenised and dehumanised.