99% of the time seems excessively high. The changes in demand are really dependent on the properties of the good in question. Also, this phenomenon is called t

99% of the time seems excessively high. The changes in demand are really dependent on the properties of the good in question. Also, this phenomenon is called the "income effect"[0]: as the price of a good Y falls relative to other goods, consumers' "income" will increase in a real sense (i.e. they'll be able to consume more of all goods), so they may increase consumption of Y, depending on whether Y is "inferior," "normal" or "luxury." The definitions of these concepts have to be made carefully to avoid circularity, but suffice it to say that 99% of goods are not normal. Energy, however, is a normal good when measured, though a 2x increase in income leads to less than a 2x increase in energy consumption for a sufficient starting level of income. (If you were living in a remote village that was only recently electrified, for instance, electricity would be a luxury good: increases in income would lead to significant increases in consumption of electricity up to a certain point.) What's more interesting is how firms react. Decreases in energy costs could lead to significant increases in productivity for firms, allowing for economies of scale that did not exist ex ante. This isn't really "consumption" per se, as energy is being "converted" into another good. But it seems likely that firms' demand for energy could increase quite a bit as the price for energy decreases. [0] https://en.wikipedia.org/wiki/Consumer_choice#Income_effect https://en.wikipedia.org/wiki/Consumer_choice#Income_effect