The information-based economy at the start of the third millennium, in contrast, is constantly changing, primarily because of rapid technological advances. Such a dynamic economy must be understood, not in terms of static physical costs of production, but in terms of marginal utility—especially as the latter is affected by information flow. The hypothetical "market without uncertainty" that we have thus far assumed is only a target, toward which the real, dynamic economy is constantly moving. In order to understand the real world accurately, we will later need to address the factors that might promote or inhibit efficient information flow, and the impact of variations in information flow upon different individuals, firms, and economic systems.

We have analyzed the pricing of consumers' goods and of labor and other factors, both depletable and durable. What return do the investors ("capitalists") receive in this market without risk or uncertainty? The investors realize their return when they bring the final good to market, where (as we have seen) they receive a price that tends toward their marginal costs of production, including interest costs (). Their net return, in other words, is simply the interest on their investment, as determined by the market interest rate and ultimately by everyone's time preferences.