Contracts are examined when outcomes depend on managers' choices as well as efforts. As the cost of effort shrinks relative to payoffs, the optimal contract converges to a linear payoff if the control space of the agent has full dimensionality, but not otherwise. Thus, when the agent can trade expected return for greater correlation with other returns, it is better to ignore relative performance when the cost of effort is small. When the choices include all fair gambles and hedges, the linear schedule is no more expensive than any other schedule that induces effort. Unfair gambles are examined as well.

Using the Mirrlees optimal income tax model with quasi-linear preferences, the paper examines conditions for marginal tax rates to be rising at high income levels and declining in an interval containing the modal skill. It examines conditions for the marginal tax rate to be higher at a low skill level than at the high skill level with the same density--an argument only holding for skill levels above a cutoff where resources of a worker are marginally of the same value as resources of the government. Data on earnings rates are presented.

Equilibrium is analyzed for a simple barter model with identical risk-neutral agents where trade is coordinated by a stochastic matching process. It is shown that there are multiple steady-state rational expectations equilibria, with all non-corner solution equilibria inefficient. This implies that an economy with this type of trade friction does not have a unique natural rate of unemployment.