CBO – “Over the next 30 years, the share of the U.S. population age 65 and older will increase from about 15 percent to almost 22 percent, spurring growing interest in understanding whether people will have adequate income in retirement. As reflected in an extensive body of literature on the topic, researchers have developed diverse approaches for quantifying the adequacy of retirement income, focusing on different groups of retirees and employing different definitions of income and adequacy. For example, some researchers have computed the fraction of current retired workers whose income is below the poverty threshold and found it to be less than one-tenth of retirees. In contrast, others who have examined how income changes upon retirement project that a much larger fraction of current workers would experience a substantial decline in income as they retire. This report explains the various measures and approaches, providing a framework for further analysis of retirement income.”