Microeconomics studies how economic units (the individual, household, and firm) make their decisions about production, consumption and saving, including
微觀經濟學研究經濟單位（個人、住戶和廠商）如何作出有關生產、消費和儲蓄的決定，包括
l the price theory
價格理論
l the theory of firms (the organization of production)
廠商理論（生產的組織）
l the distribution of income
收入的分配
l equilibrium (partial equilibrium→in one market; general equilibrium→between markets )
平衡（部分平衡→在一個市場內；一般平衡→在各市場間）
l the effect of government policy upon consumers and firms
政府政策對消費者和廠商的影響
Macroeconomics studies aggregate demand and aggregate supply, including
宏觀經濟學研究總需求量和總供應量，包括
l the circular flow of national income (employment, total production, total consumption, total investment, growth (booms and slumps), inflation (general levels of prices)
國民收入的循環流通（就業、總產量、總消費量、總投資額、增長（繁榮與蕭條））、通賬（總體價格水平）
l fiscal and monetary policies
財政和貨幣政策
l imports and exports→balance of payments
進口和出口→貿易收支平衡
l relationship between economies in an international setting
各經濟體在國際環境下的關係
Example:
The sales revenue of a firm→microeconomics （一家廠商的銷售收入→微觀經濟學）
The sales revenue of all firms (their aggregate income)→macroeconomics（全部廠商的銷售收入加起來→宏觀經濟學）No very sharp boundary can be drawn between microeconomics and macroeconomics.
微觀經濟學和宏觀經濟學難以截然劃分。
