Since the time of Alfred Marshall, more than a century ago,
economics professors have taught their students that markets
are like scissors: They have a supply blade and a demand blade that
work together to determine prices and quantities.
An example of the scissors at
work can be found in a new report on greenhouse gas emissions from the Rhodium Group.
The report is a classic case of good news and bad news. The
good news is that overall U.S. GHG emissions fell by 2.1 percent in 2019. The
evidence makes clear that both blades of the scissors are doing some cutting.
Looking first at the demand side, we see that the decrease
in total emissions comes despite an estimated 2.3 percent increase in U.S. real
GDP last year. Together, the 2.1 percent drop in emissions and the 2.3 percent
growth of GDP mean that emissions per dollar of GDP fell by a far-from-trivial
4.4 percent. American industries and consumers are finding that they don’t need
to pump out the same amount of pollution they used to in order to maintain
equivalent levels of production and consumption.