Does it make sense to subsidize biofuels?

Ina relatively short time, biofuels have become remarkably popular, especially as an additive to regular petroleum based fuel. This is at least in part due to massive subsidies from the US to fuel and corn producers. As biofuels compete with food, this has lead to major price increases for corn and sugar, with adverse consequences for importing countries. This begs the question: is it actually a good idea to subsidize biofuels? I mentioned previously that it is preferable to tax other energy products rather than subsidize alternative energies (1, 2), but let us revisit this issue.

Subhayu Bandyopadhyay, Sumon Bhaumik and Howard Wall use a general equilibrium trade model and confirm that if there is a Pigovian tax on conventional fuels, subsidies are not needed. But if the Pigovian tax is not available or too low (as is the case in the US), then a subsidy for biofuels makes sense, But if the country in question is large, there are other implications through increased worldwide demand for food. In that case, a food exporter wants to subsidize biofuels and tax conventional fuels. A food importing country would only want to subsidize biofuels if the pollution reduction effect is large enough.

Hector Nuñez, Hayri Önal, Madhu Khanna, Xiaoguang Chen and Haixiao Huang look more specifically at the interaction of policies in the US and Brazil, the two largest producers of biofuels. Indeed, the US imposes a special tariff on the importation of biofuels, in particular the more advanced sugarcane based one from Brazil. Brazil is also the largest producer and exporter of beef. The paper uses a multi-country, multi-good model, unfortunately with a partial equilibrium, but it takes into account possible crop rotations and different categories of land. It concludes that eliminating the tariffs would significantly reduce biofuel production in the US, with the latter importing biofuels from Brazil and exporting corn. While this reduces producer welfare compared to the status quo, it increases consumer welfare. Given the political system in the US, guess what will happen.