Adjusted for inflation, the income earned from wool sales by a certain family of Australian sheep farmers grew substantially during the period from 1840 to 1860. This is because the price for wool sold on the international market was higher than the price paid on domestic markets and the percentage and amount of its wool that this family sold internationally increased dramatically during that period. But even though the family generated more income from selling their wool, they failed to enjoy a commensurate increase in prosperity.

Which one of the following would, if true, help most to resolve the apparent paradox described above?