Incumbent monopolists won't command high premiums
if newcomers can rebuild capacity from scratch at a cheaper price.
At first glance, many of the nation's regional markets for wholesale electric generation appear monopolistic. In some of the 18 regional power markets we have identified, the leading companies account for 75 to 90 percent of the area's generating assets. In other markets, where the concentration problem does not yet seem as pressing, mergers and acquisitions threaten to raise levels of concentration of ownership in generation.