This document discusses several economic concepts related to unemployment including replacement ratio, poverty trap, unemployment trap, cyclical unemployment, structural unemployment, tax wedge, and centralized wage bargaining. It provides definitions and explanations of each term. For example, it explains that replacement ratio refers to the percentage of after-tax income replaced by unemployment benefits and is calculated based on disposable income when working versus when unemployed. It also discusses how a high replacement ratio can disincentivize taking a job offer.