The set of allocations that can be achieved when the only constraints upon the economic policy-maker involve technology and resources. For example, in a two-consumer exchange economy the set of first-best coincides with the contract curve of Pareto efficient allocations. First-best allocations are economically efficient, but need not be equitable. If the policy-maker is subject to constraints additional to technological and resource constraints, then only second-best allocation can be achieved. The additional constraints can include information restrictions that limit the extent of redistribution of resources that is possible.