Quantile eco-efficiency estimation and convergence: A nonparametric frontier approach

This study develops a novel quantile eco-efficiency nonparametric estimator to test for the existence of possible convergence patterns across 29 OECD countries over the period 1953–2019. Our framework provides robust eco-efficiency estimators and allows us to test the convergence of countries’ estimated eco-efficiency levels at different quantiles. The results indicate that countries’ eco-efficiency performance has been increased over the sample years, formulating specific eco-efficiency convergence clubs.