There is an important difference between domestic economic policies that create benefits by imposing costs on other nations ("beggar-thy-neighbor policies") and those whose economic costs are borne primarily at home though they might affect others as well ("beggar-thyself policies").
Beggar-thy-neighbor policies need to be regulated at the international level because a nation, left to its own devices, has the incentive to pursue zero-sum policies at the expense of others. This is the strongest argument for subjecting China’s currency policies or large macroeconomic imbalances like Germany’s trade surplus to greater global discipline than currently exists.
However, “beggar thyself” policies are not the consequence of a failure of international cooperation. They reflect either a deliberate domestic decision to sacrifice economic efficiency to a competing social value, or, in the worst case, a failure of domestic politics.
Consider, for example, agricultural subsidies, bans on genetically modified organisms, or lax financial regulation. While these policies might impose costs on other countries, they are deployed not to extract advantages from them, but because other domestic-policy motives – such as distributional, administrative, or public-health concerns – prevail over the objective of economic efficiency.
The case for global discipline is in fact quite weak with beggar-thyself policies. After all, it should not be up to the “global community” to tell individual countries how they ought to weight competing goals. Imposing costs on other countries is not, by itself, a cause for global regulation. (Indeed, economists hardly complain when a country’s trade liberalization harms competitors.) Democracies, in particular, ought to be allowed to make their own “mistakes.”
For more, see here.