The effects of consumption externalities in an R&D-based growth model with endogenous skilled and unskilled labor supply

We examine the roles of consumption externalities in a variety-expansion growth model. By assuming that the R&D sector is more skilled labor intensive than the consumption goods sector, we extend the model of Doi and Mino (J Econ Dyn Control 32:3055?C3083, 2008) so that both the skilled and unskilled labor supplies are endogenously determined through the skill acquisition process. We show that some results of Doi and Mino are influenced by our modification. For example, in contrast to Doi and Mino who show that the R&D subsidy can have a negative growth effect in the presence of consumption externalities, we show that the R&D subsidy has unambiguously positive growth effects, regardless of the presence of consumption externalities. Further, it is shown that the presence of consumption externalities influences various aspects of the economy including the wage inequality and the incentive of skill acquisition.