20230605：Zero coupon bond、Zero lower bound、Zero-hours contracts、Zero-sum game

Zero-sum game（零和博弈）：The view that economic advance by one party can only be at the expense of another.

Zero-hours contracts（临时工）：A form of employment in the gig economy that offers maximum flexibility to employers and little security to workers. Employees are summoned for work only when they are needed and cannot therefore be sure of their likely income, their availability for other jobs or child-care commitments.

Zero lower bound（零利率下限）：Central banks adjust interest rates in their attempts to stimulate or slow down the economy.

Zero coupon bond（无息债券）：A bond on which no interest payments are made.