Horizontal versus Vertical Learning: Divergence and Diversification of Lead Firms in the Hangji Toothbrush Cluster, China

L<sc>i</sc> P.-F. Horizontal versus vertical learning: divergence and diversification of lead firms in the Hangji toothbrush cluster, China, <italic>Regional Studies</italic>. Horizontal networking between competitors has long been under-conceptualized in cluster research. Combining labour mobility/spill-offs, friendship ties, professional gatherings and competitive interaction, a horizontal framework of clusters is developed as an alternative way to interpret local and external learning processes. To illustrate this framework, divergent strategies of three lead firms in the Hangji toothbrush industry, China, are investigated from the perspective of vertical linkages in global value chains and horizontal interaction in competitive networks. Although both frameworks can account for differences in strategies among these firms, horizontal interaction is particularly significant for providing additional explanations beyond producer-buyer linkages and learning.