One may be tempted to argue, that these taxes are not true CO2 taxes, rather they put price on different externalities that depend on car size
or fuel consumption per kilometer (toxic emissions, congestion, accidents, and fuel dependence). For this argument to be correct, such externalities
would need to depend on car ownership, its size, or fuel economy, but not on the number of kilometers driven or total fuel consumption. We
suggest that this is hardly the case, for as long as the car is in the garage the related externalities are close to, if not exactly, zero.