ABSTRACT
The labor theory of value is ill-suited to incorporating inputs from the natural environment into either a theory of capitalist prices or a theory of social opportunity costs. Lacking a formal framework that facilitates accounting for inputs from the natural environment and focuses entirely on how much labor time it takes to produce things, some Marxists today have scoured Marx's voluminous writings to find a few passages where he conjectured that capitalism would cause what they have labeled a "metabolic rift" between humanity and nature, and treat environmental problems as one of the "crises" that inevitably plague capitalist economies. Marx defined surplus value as the difference between the number of hours of labor needed to produce all goods and services minus the number of hours needed to produce the intermediate goods used up in the production process and the consumption goods purchased by the workers with their wages.
