Leonard Read ‘s 1958 essay "I, Pencil " is unmatched among all publications in economics in its success at conveying an immense amount of profound wisdom in a style so accessible and charming. (By the way, near the beginning of The Price of Everything  Russ does a superb job of explaining how an economics professor might introduce this wisdom to students.)
to accompany his lecture on "I, Pencil." When Roger sent this presentation to me, he commented that his effort was much easier than Leonard Read’s effort of 50 years ago. "I just used Google to get many of the details and the pictures."
Think about it. Millions of persons unknown to Roger contributed their skills, knowledge, time, and effort to make it possible for him, in just a few minutes (and at zero marginal pecuniary cost!), to create a PowerPoint presentation that will enable him to deliver a great lecture to his students. How many people helped to build the computer he worked on? To construct the cameras that captured the images? To engineer the PowerPoint software? To create and maintain search engines on the web?
The answer to each of these questions, and to each of many other similar questions that could be asked about this single, today-very-ordinary task of creating a PowerPoint presentation, is "countless." In some cases hundreds of thousands of people; in some cases hundreds of millions — perhaps billions — of people.
No one knows how to make a PowerPoint presentation. No one could possibly know all that there is to know about making a PowerPoint presentation. The creation of such presentations requires the cooperation of uncountably large numbers of people from around the globe. And yet, like the quotidian pencil, PowerPoint presentations are made and consumed everyday, and at minuscule cost.
That is the power of markets.