We revisit the issue of international technology diffusion within the framework of large panels with strong cross-sectional dependence by adopting a method which extends the Common Correlated Effects (CCE) approach to nonparametric specifications. Our results indicate that the adoption of a nonparametric approach provides significant benefits in terms of predictive ability. This work also refines previous results by showing threshold effects, nonlinearities and interactions, which are obscured in parametric specifications and which have relevant policy implications.