Appropriate military strength that is cost-efficient is an optimal position.

ECONOMIST: A helping hand

Statutory rates were too high, and deductions and exemptions too many, to make either tax collections efficient or economic activity optimal.

FORBES: Tim Geithner Meekly Phones In Tax Reform

Others argue that in a system that has an income tax, the estate tax will always be less efficient than setting the income tax at optimal rates.

ECONOMIST: Death and taxes