special issue: Knowledge, consumption, and endogenous growth

In neoclassical theory, knowledge generates increasing returns - and therefore growth - because it is a public good that can be costlessly reused once created. In fact, however, much knowledge in the economy is actually tacit and not easily transmitted -and thus not an obvious source of increasing returns. Several writers have responded to this alarming circumstances by affirming hopefully that knowledge today is increasingly codified, general, and abstract - and increasingly less tacit. This paper disputes such a trend. But all is not lost: for knowledge does not have to be codified to be reused and therefore to generate economic growth.