Should rules be simple?

The principal argument of the paper is that in an incomplete information setting, where the private sector lacks information of government objectives and has to learn about the policy rule by direct observation and estimation, simple ‘sub-optimal’ rules may outperform the more complicated rule which is optimal under complete information. This result is demonstrated by simulations using an overlapping contract rational expectations model. The paper thus provides some formal reasoning to support arguments for simplicity associated with credibility and the need for the private sector to be able to monitor policy.