A certificate of indebtedness
Budget constraint 预算约束
The limit on the consumption bundles that a consumer can afford
Budget deficit 预算赤字
An excess of government spending over government receipts
Budget surplus 预算盈余
An excess of government receipts over government spendin
barriers to entry 进入障碍
factors that prevent firms from entering a market, such as government rules or patents
basic competitive model 差不多竞争模型
the model of the economy that pulls together the assumptions of self-interested consumers, profit