Land sparing: It’s an economic question

Background/Question/Methods

Although usually seen as a simple matter of common sense, or at most as a straightforward mathematical argument based on the definition:

Yield ≡ Food Produced/Land Used

the case for land sparing involves assumptions about how the economic system works. The theoretical case for land sparing assumes that the world food system operates “to feed the world’s people” – that is, that Food Produced can be considered a constant in the short run, in which case increased Yield tautologically leads to decreased Land Used.

I examine this case both theoretically and empirically, looking at the basis for the assumptions in economics and at the case studies at various scales that have assessed whether land sparing occurs in practice. I emphasize in particular the relationship between increasing crop yields and rates of tropical deforestation. The empirical data is primarily derived from reviewing studies published in the peer-reviewed literature.

Results/Conclusions

Standard economic theory, whether neoclassical, Marxian or ecological, contrary to the land sparing argument, sees food production as an economic activity that relates to profitability rather than an activity whose objective is to produce enough food for all. If this is true, the opposite of land sparing may well be the case – that yield increases, by making agriculture more profitable, actually incentivize its expansion into natural ecosystems. Furthermore, the zero-sum view of the world that sees it as divided between “food production” and natural ecosystems, ignores the fact that globally, nearly three-fourths of the world’s agricultural land is pasture, not crop land, which leads to the necessary inefficiency of adding an extra trophic level to the food system.

Empirically, the evidence for land sparing turns out to be quite weak. Furthermore, trends in global land use over recent decades do not correspond to the zero-sum model. Economically, a plausible case can be made for turning the land-sparing argument on its head – that is, rather than increased yields sparing land for nature, increased protection for natural ecosystems, by limiting the supply of cheap land, will stimulate farmers and ranchers to increase yields.