Low degrees of substitutability for rice exist both on the demand (mill and end-use) and supply sides. On the demand side, the closest substitute is wheat, par- ticularly important in South Asia (Pakistan and India). In many Asian nations, per capita consumption of rice is declining and as a staple food it has become an inferior good with respect to income. It is being substituted out of household diets by higher protein foodstuffs such as meats, as well as by increases in the consumption of fruits and vegetables. With respect to supply, different rice varieties require different cli- matic conditions and production and milling technologies. This limits the ability of producers and millers to respond to price incentives as a guideline in selecting which type of rice to produce and mill. Rice production generally benefits greatly from ac- cess to plentiful supplies of surface water or groundwater and heavier soils that can maintain flood conditions. Although the ability to grow crops other than rice in the wet season is limited in many ecologies, there is much greater flexibility in the dry season, a season that, since the advent of the Green Revolution, has accounted for an ever greater share of rice production.