FIGURE 3-18 Old-age dependency ratio as projected by the committee, the Census Bureau, and the Social Security Trustees, 2010–2050. The central black line is the median committee forecast. There is a 50 percent probability that the ratio will lie between the green dotted lines in any year and a 95 percent probability that it will lie between the green dashed lines. The solid purple line is the 2008 Census Bureau projection. The red diamonds indicate the high, intermediate, and low variants of the 2012 Social Security Trustees projection. SOURCES: Donehower and Boe (2012), U.S. Census Bureau (2008), and Board of Trustees, Federal Old-Age and Survivors Insurance and Federal Disability Insurance Trust Funds (2012).
which 1,000 stochastic trajectories were created (see Appendix A for a description of the method used). The solid black line is the median in each year of the 1,000 random trajectories. The inner dotted green lines indicate quartiles, so there is a 50 percent chance that the future outcome will lie between them in a given year. The outer dashed green lines represent the upper and lower 2.5 percent bounds and define the 95 percent probability interval for the OADR in each year.