Is Tax sharing Optimal? An Analysis in a Principal-Agent Framework

We study the effects of a statutory wage tax sharing rule in a principal - agent framework with moral hazard (à la Holmstrom, 1979) using the approach of Bose, Pal, Sappington (2007) to model the stochastic relationship between the agent’s unobserved effort and his observed performance. The analysis indicates that tax sharing with positive legislated contributions from both the employer and employee does not maximize any of the outcomes - employee effort, wages, profits or welfare. Moreover, a rule which specifies a corner solution, with 100% of the tax statutorily levied on the employer will maximize effort, expected profit and expected welfare while 100% of the tax statutorily levied on the employee will maximize expected wages.