ABSTRACT
In some ways the idea of opportunity cost is complementary to that of marginalism. Whereas marginalist reasoning in its useful modified form concentrates on keen adjustments and flexible improvements, opportunity cost reasoning is part of the very act of choice. Practical marginalism is essentially tactical but opportunity cost tends to be more strategically oriented, more critical and, in a sense, more radical. Of the two ideas it is also the more important. If marginalism in the pure sense is unattainable – and in the modified sense a matter of optional effort – opportunity cost is inescapable and perpetually pressing in on us, whether we like it or not. It is inherent in the whole human condition, fraught with triumph and tragedy. The critical question is whether we recognise it properly and apply its rationale with lucidity.
