b'INTRODUCTION This book looks at some of the most signif- FIGURE A-1Themes of the bookicant trends and changes related to aging over the past two decades, providing information andChapter 1 considers the trend toward longer working lives, addressing factors that influ-insights that can only be found with the rich dataence decisions about how long to work and when to retire. We review HRS research that resources of the HRS. Each of the five chapters ishelps us understand how healthy we are as a nation and what influences our health in organized around a major theme (see Figure A-1).terms of work capacity at older ages. What are the consequences of retirement for health This introduction presents an overview of theand well-being? HRS study design and content, the relevance of HRS findings, and directions for the future. Chapter 2 takes up the question of the aging brain. A major contribution of the HRS The HRS is a large and complex study, but theis to provide accurate population estimates of cognitive health, including the incidence basic design is a survey that: and prevalence of Alzheimers disease and dementia. Studies that use HRS data can also Is nationally representative of the populationyield important insights about the causes and consequencesincluding the costsof over age 50 dementia. What puts us at risk for cognitive decline and what keeps us sharp at older ages? Follows individuals and their spouses orChapter 3 explores retirement preparation. As the retirement landscape continues to partners from the time of their entry into the survey until death change, workers are increasingly responsible for making sure they have adequate finan-Introduces a new 6-year birth cohort ofcial resources in retirement. Financial planners suggest, on average, that we need about participants every 6 years80% of the income while working in order to maintain our living standard in retirement. Is this realistic? Are there other ways to determine retirement resource adequacy? We review HRS research on the many personal as well as institutional factors that influence This book looks at some of theour ability to save and our decisions about saving for retirement and spending during most significant trends andretirement.changes related to aging overChapter4reviewscross-nationalcomparativeresearchthatrevealsrelativelyworse the past two decades. health in the US as compared to other developed countries, despite much higher levels of spending on health care. A deeper understanding of health disparities within the US may help us understand the cross-national gap. Particularly at middle age, health disparities This brief overview describes the surveyare very large both by race and by socioeconomic status. Health disadvantages appear to content, including external data sources to whichstart in childhood and reach into adulthood, influencing health well into older age. Where HRS data are linked, and the longitudinal cohortwe live also has a powerful influence on health.design. More detail of the study design is provid- Chapter 5 discusses the impact of the Great Recession of 2007 to 2009, looking at chang-ed in Sonnega et al. (2014).es in wealth as well as changes in work and work expectations over the period of the stock market crash, the recession, and recovery.9'