Marxist economic theory has moved away from the labor theory of value, which was a key aspect of Marx's work. However, the theory of surplus value, which looks at the difference between the value of labor and the profit made, is still relevant. The researchers suggest that this theory can be updated to focus on transaction costs rather than labor quantity. They also propose looking at capital as a unit of analysis in an evolutionary process, rather than a circular production process. This new approach offers a fresh perspective on Marx's labor theory of value.