; (4) the net benefits or costs of the implementation of such sections to the United States and the States, including— (A) the effects on electricity and natural gas demand and prices; (B) the economic development benefits of investment; (C) environmental costs and benefits; (D) the impacts on public health and health care costs; and (E) avoided costs related to environmental and congestion mitigation investments that otherwise would have been required; (5) an assessment of the benefits and costs of increasing the performance standards established under section 611(c) of the Public Utility Regulatory Policies Act of 1978 (as added by this Act); (6) the feasibility, advantages, and disadvantages of alternative models for demonstrating compliance with a Federal energy efficiency resource standard, including— (A) establishing a national trading system for energy efficiency credits; or (B) demonstrating compliance through reductions in the projected amount of electricity and natural gas delivered by retail electricity suppliers and retail natural gas suppliers, rather than on measured and verified electricity savings and natural gas savings