Loan Sharks (I)

Northern Italy in the early thirteenth century was a land subdivided into multiple feuding city-states. Among the many remnants of the defunct Roman Empire was a numerical system (i, ii, iii, iv . . . ) singularly ill-suited to complex mathematical calculation, let alone the needs of commerce. Nowhere was this more of a problem than in Pisa, where merchants also had to contend with seven different forms of coinage in circulation. By comparison, economic life in the Eastern world - in the Abassid caliphate or in Sung China - was far more advanced, just as it had been in the time of Charlemagne. To discover modern finance, Europe needed to import it. In this, a crucial role was played by a young mathematician called Leonardo of Pisa, or Fibonacci. The son of a Pisan customs official based in what is now Bejaia in Algeria, the young Fibonacci had immersed himself in what he called the 'Indian method' of mathematics, a combination of Indian and Arab insights. His introduction of these ideas was to revolutionize the way Europeans counted. Nowadays he is best remembered for the Fibonacci sequence of numbers (o, i , i , 2, 3, 5, 8, 1 3 , 21 . . .), in which each successive number is the sum of the previous two, and the ratio between a number and its immediate antecedent tends towards a 'golden mean' (around 1.618). It is a pattern that mirrors some of the repeating properties to be found in the natural world (for example in the fractal geometry of ferns and sea shells).*

(NB * The Fibonacci sequence appears in The Da Vinci Code, which is probably why most people have heard of it. However, the sequence first appeared, under the name mâtrâmeru (mountain of cadence), in the work of the Sanskrit scholar Pingala.)

But the Fibonacci sequence was only one of many Eastern mathematical ideas introduced to Europe in his path-breaking book Liber Abaci, 'The Book of Calculation', which he published in 1202. In it, readers could find fractions explained, as well as the concept of present value (the discounted value today of a future revenue stream). Most important of all was Fibonacci's introduction of Hindu-Arabic numerals. He not only gave Europe the decimal system, which makes all kinds of calculation far easier than with Roman numerals; he also showed how it could be applied to commercial bookkeeping, to currency conversions and, crucially, to the calculation of interest. Significantly, many of the examples in the Liber Abaci are made more vivid by being expressed in terms of commodities like hides, peppers, cheese, oil and spices. This was to be the application of mathematics to making money and, in particular, to lending money. One characteristic example
begins:

A man placed 100 pounds at a certain [merchant's] house for 4 denarii per pound per month interest and he took back each year a payment of 30 pounds. One must compute in each year the 30 pounds reduction of capital and the profit on the said 30 pounds. It is sought how many years, months, days and hours he will hold money in the house . . .

Italian commercial centres like Fibonacci's home town of Pisa or nearby Florence proved to be fertile soil for such financial seeds. But it was above all Venice, more exposed than the others to Oriental influences, that became Europe's great lending laboratory. It is not coincidental that the most famous moneylender in Western literature was based in Venice. His story brilliantly illuminates the obstacles that for centuries impeded the translation of Fibonacci's theories into effective financial practice. These obstacles were not economic, or political. They were cultural.

Shakespeare's play The Merchant of Venice is based on a story in a fourteenth-century Italian book called i7 Pecorone ('The Dunce'), a collection of tales and anecdotes written in 1378 by Giovanni Fiorentino. One story tells of a wealthy woman who marries an upstanding young gentleman. Her husband needs money and his friend, eager to help, goes to a moneylender to borrow the cash on his friend's behalf. The moneylender, like Shylock a Jew, demands a pound of flesh as security, to be handed over if the money is not paid back. As Shakespeare rewrote it, the Jewish moneylender Shylock agrees to lend the lovelorn suitor Bassanio three thousand ducats, but on the security of Bassanio's friend, the merchant Antonio. As Shylock says, Antonio is a 'good' man - meaning not that he is especially virtuous, but that his credit is 'sufficient'. However, Shylock also points out that lending money to merchants (or their friends) is risky. Antonio's ships are scattered all over the world, one going to North Africa, another to India, a third to Mexico, a fourth to England:

. . . his means are in supposition: he hath an argosy bound to Tripolis, another to the Indies; I understand moreover, upon the Rialto, he hath a third at Mexico, a fourth for England, and other ventures he hath, squandered abroad. But ships are but boards, sailors but men: there be land-rats and water-rats, water-thieves and land-thieves, I mean pirates, and then there is the peril of waters, winds and rocks.

to be continued...