Interesting graph showing 'energy as a share of nominal consumer spending.' This is 'energy' not just gas, but I am sometimes casual in using one as a proxy for the other...
https://angrybear.blogspot.com/2008/...-consumer.html
It looks like for over 20 years we have been spending a lower and lower proportion of our money on energy.
I think this might help understand why demand for energy is relatively inelastic. Economic theory would suggest that we use less energy as the price goes up, but mostly that hasn't been true in the US (I did see the reported 1% year to year decrease in miles driven in April, or was it March?)
Some people argue that our inelastic demand for energy means that we are basically incapable of changing our consumption habits, and so peak oil triggered supply shortages will cause death, destruction, and doom.
Looking at these % of spending numbers offers a different way to understand our apparent inelastic consumption, and that is that mostly we are either trapped into using the energy, or we value what we get from using the energy more than the price.
When energy is a % of spending varies between 4-9% they do not seem to be highly linked with changes in consumption.
So the question gets flipped from 'how high does gas have to go before we change behavior?' to 'how high, as a percentage of consumer spending, does gas have to go before we change behavior?'