But some economists and academics say such changes may have a better shot if states continue to lead, although it will depend how well they do so. For example, the Northeast’s landmark Regional Greenhouse Gas Initiative, which set a gradually lowering cap on power plant emissions with the intent of driving up the cost of carbon emissions for operators, has not sparked the investment in pollution reduction first envisioned. Emissions have been markedly lower than forecast because of the recession, and low natural gas prices and a cap that was set very high also made the program less effective. However, a cap and trade program that is beginning in California could have a significant national impact, analysts say.