are induced by regulations. However, innovation that increases a firm’s material or energy efficiency in terms of material … voluntary innovations, although the effect is significantly larger for regulation-driven innovation.We conclude that the Porter … hypothesis does not hold in general for its “strong” version but has to be qualified by the type of environmental innovation. Our …

are induced by regulations. However, innovation that increases a firm's material or energy efficiency in terms of material … voluntary innovations, although the effect is significantly larger for regulation-driven innovation. We conclude that the Porter … hypothesis does not hold in general for its strong version but has to be qualified by the type of environmental innovation. Our …