In general, the gains to some resources from free trade exceed losses suffered by other resources. This means that, in principle:

• the government should tax imports in order to reduce the losses suffered by some resources.
• the government ought to tax returns on land because these always increase with free trade.
• the government should be able to tax resources that gain and compensate resources that lose, so all resources are better off with trade.
• the government ought to tax exports in order to collect revenue to compensate resources that lose from free trade.