Vertically integrated utilities support the formation of ISOs because it preserves their ownership position in Transmission. Borenstein, S., Bushnell, J., Kahn, E., and Stoft, S., Market Power in California Electricity Markets , March 18, 1996. Borenstein, Bushnell, Kahn, Stoft, page 11. Shepherd, William G., The Economics of Industrial Organization, Third Edition. Page 53. 6.
Consumers can additionally self-generate.
Borenstein, Bushnell, Kahn, Stoft, page 11. This permits higher profits than if only one uniform price were set. Borenstein, Bushnell, Kahn, Stoft, page 14.