Multiple Market-Clearing Prices, Electricity Market Design and Price Manipulation. William Hogan, March 31, 2012, Paper. "Integration of physical transactions and financial contracts is central to successful electricity market design. Virtually every energy transaction has some impact on prices. The mere fact that a physical transaction can affect prices to some degree, and thereby influence the prices of related financial contracts, cannot be a per se definition of price manipulation. A principled policy for characterizing price manipulation in organized electricity markets includes a stand-alone profitability test. Multiple..."