Which political party is better at improving living standards?
A commonplace view is that Democrats favor policies that boost the well-being of the poor while Republicans’ policy preferences are more conducive to economic growth and rising incomes. Debates about high vs. low taxes, generous vs. stingy social programs, and heavy vs. light regulation of business often are framed in terms of a tradeoff between compassion and growth. Should government do more to assist the poor? Or should it intervene less, thereby helping the economy to grow more rapidly?
For the most part this debate is a battle of rhetoric and assumptions. Many on the right assume that lower taxes, less regulation, and less generous social policies must be good for economic growth. Some on the left accept this assumption but argue that growth will fail to trickle down to the poor. Others dispute the assumption.
Evidence can help. There is a great deal of it that is potentially relevant. Here is one piece. Using tax records and surveys, the Congressional Budget Office has compiled good data on household incomes from 1979 through 2005 (here). The presidency was held by a Republican from 1981 to 1992, by a Democrat from 1993 to 2000, and by a Republican since 2000. The following chart shows average rates of income growth (adjusted for inflation and with taxes subtracted) for each of the five quintiles (fifths) of households during these three periods.
Income growth for each of these groups, from the poorest to the middle to the richest, has been faster during Democratic administrations than Republican ones.
Does this prove that Democrats are more effective than Republicans at promoting income growth? No. A government’s ability to affect income growth is limited, Democrats controlled one or both houses of Congress during Republican presidencies and vice-versa, and each of these periods has idiosyncratic features (see here, here, and here, for instance). Still, the data offer reason for skepticism about the notion that policies favored by the right are better at raising living standards.
Nor is this peculiar to the American context. Here is a counterpart chart showing income growth in the United Kingdom over the same period. The Conservative party held the government from 1979 to 1997; the Labour party has held it since. The data are from the Institute for Fiscal Studies (here).
Incomes of the richest fifth increased slightly more rapidly during the years of Conservative government, but most British households have fared as well or better under (New) Labour.