The two economists — Guglielmo Barone and Sauro Mocetti of the Bank of Italy — compared data on Florentine taxpayers in 1427 against tax data in 2011. Because Italian surnames are highly regional and distinctive, they could compare the income of families with a certain surname today, to those with the same surname in 1427. They found that the occupations, income and wealth of those distant ancestors with the same surname can help predict the occupation, income and wealth of their descendants today.

As they wrote for the economics commentary website VoxEU, “The top earners among the current taxpayers were found to have already been at the top of the socioeconomic ladder six centuries ago.”

Their research was made possible by a fiscal crisis. In 1427, Florence was near bankrupt from an ongoing war with Milan and so the Priors of the Republic conducted a tax census of about 10,000 citizens. They took stock of the name and surname of the head of household, their occupation and their wealth.

About 900 of those surnames are still present in Florence, with about 52,000 taxpayers having those names. The authors note that Italian surnames are especially good for this effort, because they are highly regional.  While not every person with a certain surname in Florence today will be a descendant of the people with that name in 1427, it’s a good bet that most are. To see how these “families” had fared over the intervening six centuries, they compared the surnames against Florence’s 2011 tax records. (As a condition of access to this data, the authors did not publish the surnames.)

They find strong evidence that socioeconomic status is incredibly persistent. The wealthiest surnames in Florence today belong to families that, in 1429, were members of the shoemakers’ guild — at the 97th percentile of income. Descendants of members of the silk guild and descendants of attorneys — both at the 93rd percentile in 1427 — are among the wealthiest families today.

Some of the wealthiest families in Florence today had ancestors who were prosperous shoemakers in the 1400s. Here, Salvatore Ferragamo–who died in 1960 and thus was not in the scope of this report–shows off his Florentine workshop where he made shoes for celebrities.

It’s no surprise that wealth can be inherited or that one’s parents play a large role in determining your social status. Other research has found that descendants of Japan’s samurai – 140 years after the end of the order — remain elites in Japan. The economist Gregory Clark at the University of California, Davis, has written a book “The Son Also Rises” showing how wealth and status can persist for centuries.

Still, the length that Florentine families have remained high status remains remarkable. Consider, in 1427, the Renaissance masters Leonardo da Vinci and Michelangelo had not been born. Florence would go from rule under the Medici family, to a Republic, back to the Medici.The city would fall to the Holy Roman Empire following the 10-month Siege of Florence. The Medici line would go extinct, the city would be taken over by Napoleon. It would lose its role as the head of a city-state to become part of the Kingdom of Italy, under Rome. The fascist dictator Benito Mussolini would rule from 1922 to 1943, followed by a Nazi occupation of Florence. Following the war, the city would undergo a period known as the “miracolo economic italiano” — the Italian economic miracle — with GDP growing more than 8% a year. Per capita GDP would grow more in this period than in the entire five centuries from 1400 to 1900.

One might be quick to draw parallels to the research of Thomas Piketty, the French economist who documented the rise of income inequality, especially at the top 1%. The authors resist that link.

“The paper is about economic mobility (or persistence), that is whether the rich remain the rich,” the economists wrote in an e-mail from Mr. Mocetti, “But this does not necessarily imply that they are getting ever richer. Therefore there is not a direct relation with the Piketty argument (increasing inequality over time).”

The economists say their evidence suggests persistence is somewhat highest for the wealthiest, which they interpret as evidence for “the existence of a glass floor that protects descendants of the upper class from falling down the economic ladder.”

But they note their research is not focused on the super elite at the top 1% of income. Their finding is for the overall population. The entire top 33% of the income distribution in 1427  is likely to be wealthier today. This is a far broader group than Medici princes and dukes, with castles and estates to hand down through the centuries. This suggests that some 25 generations later, the hundreds of descendants of comfortable — but far-from-regal — leathermakers are likely to be doing quite well, and it’s not because they inherited great(x25)-grandpa’s shoes and belts, let alone his palaces.

This evidence suggests social class persists up and down the scale, for wealthy families and middle-class and poor, through renaissance and economic boom, through busts and upheavals, through military occupations and overthrows, through republics and kingdoms and dictatorships and for centuries and centuries.