From Cold Spring Shops:
Here's a pop quiz the Berkeley Energy Institute gave to readers.Which of the following two choices leads to more fuel savings:
(A) buying a 15 mpg Cadillac Escalade instead of a 12 mpg Chevrolet Suburban, or
(B) buying a 50 mpg Toyota Prius instead of a 29 mpg Toyota Corolla?
Read it carefully: it's decision making at the margin. Ceteris paribus conditions are provided for the readers. "Assume you would drive the same distances and speeds no matter which car you have." Thus the total fuel use will be the least with the Prius and the greatest with the Suburban.
Click through to the post "Rectangular Hyperbolas" if you want to see the answer.
I care about this because the misinterpretation of nonlinearity in this example is very close to the misinterpretation of nonlinearity in casual analysis of macroeconomic policy and events. For example, it's really easy for dim bulbs in the legacy media to claim the the Great Recession was comparable to the Great Depression if they don't log the real GDP data first.