The economist Julian Simon argued in 1980 that overpopulation is not a problem as such and that humanity will adapt to changing conditions. Simon argued that eventually human creativity will improve living standards, and that most resources were replaceable. Simon stated that over hundreds of years, the prices of virtually all commodities had decreased significantly and persistently. Ehrlich termed Simon the proponent of a "space-age cargo cult" of economists convinced that human creativity and ingenuity would create substitutes for scarce resources and reasserted the idea that population growth was outstripping the Earth's supplies of food, fresh water and minerals. This exchange resulted in the Simon–Ehrlich wager, a bet about the trend of prices for resources during a ten-year period that was made with Simon in 1980. Ehrlich was allowed to choose ten commodities that he predicted would become scarce and thus increase in price. Ehrlich chose mostly metals, and lost the bet, as their average price decreased by about 30% in the next 10 years. Simon and Ehrlich could not agree about the terms of a second bet.
