Social Security Bulletin, Vol. 73 No. 2, 2013

## Text description for Chart 1.

Distribution of contribution amounts in 2007 and their percentage change during the crisis period (2007–2009)

Chart 1 is comprised of two separate charts. The first one shows the frequency distribution of 2007 contribution amounts as bar charts overlaid by kernel density function. The x-axis denotes the dollar amount from zero to the maximum amount of contributions, with each bin width of $500. The y-axis shows the percentage of the sample within each bin. The distribution of contributions is skewed to the left, indicating that the median contribution amount is smaller than the mean. The second chart shows the frequency distribution of the percentage change in contributions in 2009 compared with that in 2007 as bar charts overlaid by kernel density function. Thus, the x-axis shows the percentage point change, which ranges from -100 percent to +100 percent. Here each bin has a width of 5 percent. The median percentage change is -2.2 percent, and for about 37 percent of the sample the percentage change in contributions fell within plus or minus 15 percent. Around 16 percent of the sample stopped contributing (that is, their contributions from 2007 through 2009 changed by -100 percent), and about 9 percent of the sample started contributing over the period (that is, their contributions changed by +100 percent).

## Text description for Chart 2.

Distribution of contribution amounts in 2005 and their percentage change during the precrisis period (2005–2007)

Chart 2 is also comprised of two separate charts. The first one shows the frequency distribution of 2005 contribution amounts as bar charts overlaid by kernel density function. The x-axis denotes the dollar amount from zero to the maximum amount of contributions, with each bin width of $500. The y-axis shows the percentage of the sample within each bin. The distribution of contributions is skewed to the left, indicating that the median contribution amount is smaller than the mean. The second chart shows the frequency distribution of the percentage change in contributions in 2007 compared with that in 2005 as bar charts overlaid by kernel density function. Thus, the x-axis the percentage point change, which ranges from -100 percent to +100 percent. Here each bin has a width of 5 percent. The median percentage change is -1.9 percent, and for about 44 percent of the sample the percentage change in contributions fell within plus or minus 15 percent. Around 13 percent of the sample stopped contributing (that is, their contributions from 2005 to 2007 changed by -100 percent) and about 12 percent of the sample started contributing over the period (that is, their contributions changed by +100 percent).