A bivariate random effect panel data model is estimated for male labour supply in the taxable and the non-taxable sectors in Denmark. The wage rates and non-labour income have significant effects on labour supply in both sectors. The average own wage elasticity with respect to underground labour supply is found to be small, 0.02, while the cross price elasticity from regular wages is larger, 0.52. Simulations of potential tax reforms show that a reduction of the marginal taxes has minor effects on male labour supply to the untaxed sector, while the effect on male labour supply to the taxed sector is larger.
Labour Economics, 2005, Vol 12, Issue 5, p. 613-628