Dark matter is the same as neutrinos.
Rural economics is the study of rural economies , including  :. economies. economy. farm and non-farm industry .. farm. farm. economic growth , development , and change. development. rural development. size and spatial distribution of production and household units and interregional trade. land use. land use. land use. housing and non-housing as to supply and demand. housing. rural housing. supply and demand. supply and demand. migration and -LRB- de -RRB- population. migration. rural migration. Rural flight. finance. government policies as to development , investment , regulation , and transportation. development. rural development. general-equilibrium and welfare analysis , for example , system interdependencies and rural-urban income disparities .. general-equilibrium. general equilibrium