In her July 31 letter, PennFuture's Jan Jarrett displayed an invincible ignorance of the laws of economics. The proposed state mandate on Pennsylvania power plants, which offers no measurable benefits to human health or environmental quality, would impose huge costs on electricity providers, resulting in powerfully negative effects on our economy.

"Installing pollution controls creates jobs by creating productive work," Jarrett blithely asserts. In fact, electricity providers may decide the unscientific, politically-motivated mandate is too expensive to meet and will choose to shut down operations rather than make uneconomical upgrades. This in turn will reduce the amount of electricity available to Pennsylvania consumers, resulting in higher prices for everyone.

Contrary to her assertions, the volume of power generation provided by coal-fired plants simply cannot be replaced with wind power, solar panels or any other fashionable "alternative" source. The proposed mandate is nothing more than a new energy tax that will create a further drag on Pennsylvania's competitiveness.

As consumers demand record levels of electricity to cope with the August heat, Pennsylvania lawmakers should defend the public interest and thwart the efforts of environmental extremists to raise energy prices. DAVID N. TAYLOR Executive Director, Pennsylvania Manufacturers' Association Harrisburg