by Michele Belloni, Rob Alessie, Adriaan Kalwij and Chiara Marinacci; CeRP WP N. 129/12
European studies highlight a widening of relative inequalities in general mortality by socioeconomic status from the 1970s to the 1990s. Few studies are available for Southern European countries; they show that these countries represent an exception to these trends. Available evidence on this for Italy is for a specific city only and nationwide evidence does not exist yet.
This paper examines the association between lifetime income and old age mortality risk, referred to as the income–mortality gradient, in Italy during the 1980s and 1990s. We investigate the shape of the gradient. Most importantly, we analyze the evolution of the gradient between these two decades.
We use data drawn from an administrative pension archive held by the main Italian social security institution and proxy individual lifetime income with pension income. We use non-standard Cox proportional hazard models, where the positions and number of the knots in the spline function for income are determined by the data.
The shape of the income–mortality gradient shows two discontinuities for males and one for females; these kink points are situated almost at the same percentiles of the income distribution during the 1980s and the 1990s. The estimated associations are negative and stronger at higher income levels. The income–mortality gradient widens over time for males and remains unchanged for females. Accounting for regional effects explains most of the widening in the gradient over time for males.
Our findings show for both males and females that mortality risk decreases with income. Once controlled for regional differences, and in contrast with the trends observed in many other European countries, the relative difference in mortality risk between high and low-income individuals is rather stable over time in Italy.