The Harvard economist Greg Mankiw weighs Sen. John McCain’s views on carbon trading against Sen. Barack Obama’s.
“Over time an increasing fraction of permits for emissions could be supplied by auction,” McCain said, “yielding federal revenues that can be put to good use.”
“Not bad,” responds Mankiw, “but … why over time? Why not immediately? And how high would that fraction become?”
Mankiw likes Obama’s support of a cap-and-trade system through “a 100-percent auction.”




