I recently stumbled across two studies that trace family fortunes over centuries by tracing their surnames. One posits that the same families that were rich in Venice in the 15th century are still rich today. The other one makes the same argument for England spanning the time from 1170 to 2012. This is remarkable. From the second study:
Using educational status in England from 1170 to 2012, we show that the rate of social mobility in any society can be estimated from knowledge of just two facts: the distribution over time of surnames in the society and the distribution of surnames among an elite or underclass. Such surname measures reveal that the typical estimate of parent–child correlations in socioeconomic measures in the range of 0.2–0.6 are misleading about rates of overall social mobility. Measuring education status through Oxbridge attendance suggests a generalized intergenerational correlation in status in the range of 0.70–0.90. Social status is more strongly inherited even than height. This correlation is unchanged over centuries. Social mobility in England in 2012 was little greater than in preindustrial times. Thus there are indications of an underlying social physics surprisingly immune to government intervention.
The authors argue that the common measure of correlation in socioeconomic status between parents and children is misleading, as we see a lot of randomness on shorter time scales. If the correlation is status between children and parents really were only around 0.2 – 0.6, we should rarely observe families do well over centuries. The fact that we do suggests we may be overestimating the extent of social mobility by quite a lot.
I haven’t gone through the studies in detail and cannot tell whether they are solid. But I find this finding intriguing enough to share. If you know more about it, contact me or post a comment.