“…The empirical literature provides a spectrum of findings ranging from little/no effect (Gelb, ; Sala‐i‐Martin and Subramanian, ; Black et al ., ; Caselli and Michaels, ), positive (Greasley and Madsen, ; Smith, ; Allcott and Keniston, ), to negative effect (Ismail, ; Rajan and Subramanian, ; Charnavoki and Dolado, ; Harding and Venables, ). Our model identifies in the substitutability between labour and commodity a key conditioning factor capable of rationalising this pattern.…”