Do cluster policies make firms more collaborative ? The case of the French cluster policy

The classic arguments justifying public intervention in favour of innovation revolve around the will of the public authorities to reduce the market failures limiting private investment in innovation activities. However, as more recently highlighted by the innovation system literature (see Bleda and Del Rio, 2013 for an overview), systemic failures also occur. These latter refer to structural, institutional and regulatory deficiencies, which lead to sub-optimal investment in innovation activities. One of the main structural deficiencies is the insufficient and/or inefficient levels of networking and knowledge exchange between organisations; this deficiency is referred to as ? network failures? Thus, innovation policies no longer aim at addressing market failures only, and many modalities of public intervention also focus on addressing systemic failures. This is particularly the case for cluster policies whose main objective is to address network failures. The expansion of cluster policies across the world finds its roots in the expected benefits from collaborative innovation and from the geographical concentration of firms and economic actors. Indeed, R&D cooperation allows the reduction of the inherent risks associated with R&D projects by i) promoting knowledge and cost sharing between collaborators, ii) increasing likelihood of successful R&D activities and iii) internalizing spillovers. Furthermore, the literature on spatial agglomeration and more recently on regional innovation systems argued that the concentration of economic actors generates spillovers that have positive effects on regional growth. According to this literature, strengthening the links between the actors of a territory generates knowledge flows which, once recombined, strengthen the actors’ capacity to produce innovations, and then territorial growth. Given these theoretical arguments justifying the implementation of cluster policies, it is necessary to evaluate to which extent they influence the structuration of innovation networks, i.e. how organisations change their collaboration patterns as a reaction to the policy. Most evaluations of cluster policies have been however largely focused on market failures by looking at the effects on organisations innovation inputs (R&D expenditures) or on their outputs (productivity, patents, employment, etc.). Only few recent studies have examined the effects of cluster policies regarding network failures (for example Cantner et al., 2017). But the literature on this issue remains embryonic, especially regarding the behavioural additionality of cluster policies, and it faces methodological difficulties. In this paper, we study the effects of the French cluster policy on the co-invention rate of cluster members during the period 2008-2010. Our goal is to identify to which extent this policy has influenced the collaborative behaviour of cluster members. Using patent data from the French patent office, we test (i) whether cluster members are more engaged in co-inventions, and especially, (ii) with co-located organisations. We combine Inverse Probability of Treatment Weighting (IPTW) with a difference-in-difference estimator in order to address the causal effects of cluster membership. A doubly robust estimation and a sensitivity analysis are also implemented in order to address a potential lack of confidence in the assumptions underlying that assessment. Compared to past studies, instead of observing collaboration networks directly from projects supported within clusters, we rely on external data, namely patent data, to investigate whether cluster participation induce a change in the innovation process itself. The novelty of the paper is thus twofold. First, while the evaluation of cluster policy literature concentrates on input and output additionality, we shift the focus towards collaboration additionality. Second, we use external-to-the-policy data (patents) to build upon a counterfactual analysis. To the best of our knowledge, this is therefore the first study to conduct a causal evaluation of cluster policy regarding network failures. We found that the French cluster policy significantly influenced the collaborative behaviour of their members during the period 2008-2010. Clusters allowed their members to be more engaged in coinventions: cluster members have increased their co-invention rate by 3.4 percentage points as a result of their membership. However, we did not find evidence that cluster members were more engaged in collaborations involving co-located partners. This result therefore supports the partial effectiveness of the French cluster policy in tackling network failures. Bleda, M. , & Del Rio, P., 2013. The market failure and the systemic failure rationales in technological innovation systems. Research policy, 42(5), 1039-1052. Cantner, U. , Graf, H. , T? pfer, S. , 2017. Structural dynamics of innovation networks in German LeadingEdge Clusters. Journal of Technology Transfer, doi:10.1007/s10961-017-9642-4.