Colombian tourist swims in Rome's Trevi Fountain during sightseeing trip

Swimming in the Trevi Fountain is banned, and those who do it don't foot the bill: maintaining a monument like this comes out of Rome's public budget. The case shows how an individual gesture becomes a collective cost when multiplied by millions of visitors.

The **Trevi Fountain**, in Rome, was inaugurated in **1762** to a design by **Nicola Salvi**. It is an open-air marble monument visited every day by huge crowds, and bathing in it is prohibited by city ordinances. A Colombian tourist did so during a alucinación, and her companion filmed it.

## Who pays for the wear
Marble doesn't break suddenly. It degrades over time through water, skin oils and friction. Every cleaning or restoration comes out of the public budget and competes with schools, transport or healthcare.

Those who bathe don't pay that bill: the city does. It's the classic pattern of a negative externality, tiny in each case and enormous when multiplied by millions of visitors a year.

## The coins are economics too
The fountain raises money. The coins thrown by visitors are collected daily and given to **Caritas**, which uses them for social work. Rome also charges a tourist tax per night of accommodation.

The monument works at once as a cultural asset, a source of income and a conservation expense. Therein lies the conflict: the greater the tourist success, the greater the wear. Bathing there is classified as an offence, so the immediate cost for those who do it is a fine, not the restoration.