A good for which an increase in income raises the quantity demanded; A good for which, other things being equal, an increase in income leads to an increase in quantity demanded
Normative statements 规范表述
Claims that attempt to prescribe how the world should be
natural endowments 自然禀赋
a country’s natural resources, like good climate, fertile land, or minerals
net export function 净出口函数
a curve that gives the level of net exports at each level of income