The wealthiest families in Florence are the same families that sat at the top of the socioeconomic ladder almost 600 years ago, economic research has found.

Analysing Florentine tax records dating back to 1427, economists Guglielmo Barone and Sauro Mocetti discovered that the individuals with the highest income in Florence in 2011 had the same surnames as the wealthiest individuals almost six centuries earlier.

Nine hundred of the surnames found in 1427 tax records can still be found today, and there are 52,000 Florentine taxpayers with these surnames.

The regional nature of Italian family names means that though it is not definite that people with the same surname are related, it is highly likely, and therefore surnames can be used in research to indicate direct descendants.

Findings show that changes in wealth and status from generation to generation in Florence were minimal, with little opportunity in Florentine society to move up the socioeconomic ladder.

For example, modern members of the Bernado family, who were in the 90th percentile of earnings distribution in 1427, earn five per cent more (adjusting for age and gender) than modern members of the Grasso family, who were in the 10th percentile in 1427.

In an article published on VoxEU, revealing their findings, Mr Mocetti and Mr Guglielmo said that not only is low social and economic mobility unfair, but it may also disadvantage the society as a whole: “Societies characterised by a high transmission of socioeconomic status are not only more likely to be perceived as ‘unfair’,” they said. “They may also be less efficient as they waste the talents and skills of those coming from disadvantaged backgrounds.”

Mr Mocetti and Mr Gugliemo say that other researchers have underestimated the effect of family status, assuming that the any advantages or disadvantages owing to the status of ancestors are almost 'wiped out' within three generations.

Why do the rich get richer?

However, tax records show evidence of a “glass floor”, which prevents the wealthy from falling below a certain point on the socioeconomic ladder.

Florence is unlikely to be unique in its lack of socioeconomic mobility – the research was conducted in this particular city because, due to a fiscal crisis, the Priors of the Republic recorded the surname, occupation and wealth of each head of household in 1427. The relative uniqueness of Italian surnames also made Florence a good candidate for this kind of research.

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Intergenerational income elasticity – the ease at which individuals can change their income and status levels across generations – is measured on a scale of 0 to 1, where 0 would mean complete intergenerational mobility and 1 mean a complete inability to change income or status between generations.