Some products have characteristics that lead firms to compete to be the supplier of a whole market of product or services, rather than for market share (whether it be a share of units, of contracts or of consumer relationships). These might for example include: a) natural monopolies (with large economies of scale); b) publicly-funded monopolies (that would not be provided by markets); c) legally-protected monopolies (e.g. products protected by intellectual property rights); and d) platform monopolies (e.g. digital platforms with powerful direct or cross-platform network effects that generate increasing value from scale). This Roundtable will focus on the first of these categories, natural monopolies, and publicly-funded monopolies, particularly on the enforcement challenges that arise when concessions are offered on these services.