East Hampshire began to pioneer a scheme known as "private provision", which means public houses, restaurants or churches agree to provide toilets for the general public in return for an annual sum from the council.

BBC: Save our loos plea

The church is offering a four-figure sum of money for information that leads to the return of the jewellery.

BBC: Ring

Currently run by Severn River Crossing Plc, the bridge will return to public ownership when the firm has collected a fixed sum of money from tolls, expected to be around 2017.

BBC: Welsh Affairs Select Committee

Your total return on an investment is the sum of dividends and capital gains.

FORBES: Let Your Landlord Sweat Instead

But some firms, most famously Matsushita, a big electronics manufacturer, have introduced a new scheme in which employees waive the lump sum at retirement in return for a higher salary.

ECONOMIST: Still work to be done

Then, if such a family's tax return suggests its income is substantially lower than that sum the authorities might get suspicious.

BBC: Italian tax dodgers uncovered by the Redditometro

The five-year performance quoted above (like the ones in the tables beginning on page 136) is a time-weighted return, measuring results for a hypothetical investor who put in a sum at the beginning and stood pat.

FORBES: The fortunes of an aggressive growth fund in a bear market.

But a lump-sum investment at the beginning would have earned you an annual average total return of 3%.

WSJ: The Intelligent Investor: Think Twice Before You Buy on the Dips

We may not return specifically to mercantilist models, but whatever comes next will share the essential zero-sum feature.

FORBES: Warren Buffett, Peter Thiel and the Return to Zero-Sum Economics

Whenever someone in the working poor or middle class receives a large sum of money, such as a tax return, he will usually spend all of that money.

FORBES: Average America vs the One Percent