While I agree with the general point, it seems bizarre to include agricultural subsidies as an example of a "beggar thyself" policy. French agricultural subsidies promote the indirect export of cheap wine, for example, although it is correct to point out that wine is not differentiated by price alone. The most egregious example of a global beggar-thy-neighbor agricultural subsidy is in the United States, where massive subsidized agricultural production is funneled into cheap exports. Perhaps your article should contain the caveat that the agricultural subsidies in question are only "beggar thyself" policies if agricultural production is not significantly exported across national boundaries, i.e. it is domestically consumed, as in China.