This paper discusses the interdenpendencies that exist between vertically-linked industries in the (Spence-)Dixit-Stiglitz model of monopolistic competition. The main objective is to develop a concept for quantifying the magnitude of sectoral coherence in models of the New Economic Geography. It is motivated by the suggestion, by Venables (1996), that `strategic industries` be identified in terms of their agglomeration potential. Using a partial-analytic approach, we focus on inter-industrial relations in a closed economy to draw conclusions regarding international trade. We ascertain that two factors have an impact upon the strength of industrial linkages: 1) the monopolistic scope of intermediate suppliers, in terms of (technical) substitution elasticity; and the share in downstream costs for intermediates. Within a simulation study, this paper applies this new theoretical concept to eight basic industries across ten European countries.