What a Fuel 'Share' Hides When Gasoline Is in the Denominator

Econbrowser flags a statistic borrowed from Nate Silver: each state's diesel and heating oil dependence, measured as a share of total diesel + heating oil + gasoline consumption volume. The blogger's verdict on the measure is that it is somewhat strange, and the arithmetic explains why a share can be odd without being wrong. A share is a ratio, not a size. Put gasoline in the denominator and a state full of drivers gets a huge number at the bottom of the fraction, which flattens whatever diesel and heating oil sit above it — not because those fuels matter less there, but because there is more of everything else. Conversely, a place that burns little fuel overall could post a large percentage while consuming modest amounts of diesel in absolute terms. The numerator matters too: it bundles diesel with heating oil, so the figure is really a blended distillate number rather than diesel alone. Anyone reading it as pure trucking, farming or home-heating exposure is reading one combined quantity and guessing at the mix inside it.