This note is a part of my Zettelkasten. What is below might not be complete or accurate. It
is also likely to change often.
In many types of markets where knowledge of the marketplace is centralized and controlled, like the online-search driven markets and art marketplaces, the few who are able to take advantage of this are able to create monopolies.
This is common in more centralized markets. In marketplaces where the knowledge of the buyers and sellers reside in a few entities, the few who are able to understand to take advantage of this situation are able to create monopolies. Some examples of this happenning are : major auctionhouses and tastemakers control the art world, google controls the knowledge of buyers and sellers through online search and AppStore)
One kind of knowledge scarce marketplaces are Winner-takes-all markets. These are makets which rewards a few winners exponentially more than the others. Examples of these are sportspersons, artists or the entertainment industry, even the ratings system of amazon or the SEO of google search. These markets might even look like meritocracies where the top performers are getting a just reward. The reality is that these markets have strong feedback loops (related to the scarcity of knowledge mentioned above and Availability Heuristic) which amplify small initial differences into enormous difference in final outcomes (also called luck). This situation is almost similar to Central Planning where a central entity determines the winner instead of random happenstance.
In distributed markets, the information about the players in the markets are more distributed and monopolies are less likely to be formed. Related to Jury theorem or the wisdom of the masses.