The objection I have to cap and trade systems is that they depend on carbon certificates and they depend on those carbon certificates being limited. The experience in Europe is that political imperatives will then change the number of certificates. This means trusting that we're not going to just print more certificates when a political imperative comes up.
All the discussion in America around the coal-fired industry, which is 50% of electricity in the United States, saying that they have to be given certificates for this whole thing to work, to me just defeats the whole idea of it in the first place. The carbon tax, as I said, is a far more neutral, less distorting way to do it, because it allows consumers, based on price decisions, to make decisions about emissions rather than allowing people to make them based on who's going to get the certificates.