The economics of spam

Junk emails cost $20bn a year. Not just an irritation.

Here's a fascinating new paper (pdf) from the Journal of Economic Perspectives on the economics of spam, by Justin Rao and David Reiley:

The negative externalities imposed by spam include wasted time for consumers: both wading through irrelevant advertisements in one’s inbox and missing an important message that went to the junk mail folder. They also include the costs important message that went to the junk mail folder. They also include the costs of server hardware, which requires more than five times as much capacity as would be required in the absence of spam, as well as the costs of spam prevention services provided by firms to reduce the burden on users. . .

Taken together, the total costs of spam worldwide today appear to be approximately $20 billion, in round numbers.

The authors review literature on the revenue of spammers, and find that it's likely to be around $300m a year. In other words, spam destroys around $19.7bn dollars of value every year. The authors compare this to car theft, which imposes societal costs of around $10bn and brings revenues to the thieves of around $1bn; and to driving a car, which imposes societal costs of around five cents a mile and brings in average revenue of around 60 cents a mile.

Clearly all these numbers are extremely rough estimates, but if they are even in the same ballpark as the truth then it is clear that spam ought to be a public policy priority to a far greater extent than it actually is. Imagine if the number of car thefts doubled overnight; would people really question whether that calls for governmental involvement?

The problem the authors identify is one of negative externalities, similar to the issues raised by carbon emissions. So one would expect the solution to be analogous to the solution economists often call for to deal with externalities, which is a Pigovian tax - charging someone who harms society an amount equivalent to the damage they do. Unfortunately, as the authors show, such a measure is pretty much impossible when it comes to email spam. The spammers would obviously not co-operate, and every alternative involves trying to graft on some form of payment mechanism to email, which is a protocol incredibly unsuited technologically to any such addition.

Instead, the best thing to do is probably to hit the spammers where it hurts: their revenues.

One fruitful avenue is to put legal pressure on domestic banks that process payments from foreign banks known to act on behalf of spam merchants. This could put downward pressure on conversion rates and with them, proifts. Another proposal comes from our colleague Randall Lewis, who imagines “spamming the spammers” by identifying spam emails and placing fake orders on spam-advertised stores. This step would increase the merchants’ costs dramatically, as they would find it much more difficult to fullfil orders, and their banks may raise their fees if they submit many invalid payment authorization requests. Of course, an unintended consequence is that from time to time, a legitimate merchant will be inundated with bogus product orders.

Commenting on the paper, Digitopoly's Joshua Gans points out that, under US law, that may not be entirely legal:

A few years back I contacted Yahoo and Google with an idea to counter spammers. What if for each spam email that they picked up, they responded — perhaps entering details into phishing forms? This would overwhelm spammers and they would not be able to find ‘legitimate’ responses from the gullible few. That would really alter their returns. Unfortunately, it was explained to me that such a measure would constitute an attack by a US corporation and, apparently, that is against US law.

Spam may be here to stay, then. The real solutions are technological, and don't involve fixing email so much as abandoning it altogether; the time for being able to accept free, unsolicited email from anyone seems to be coming to an end. Those who are trying to build its replacement will be happy indeed to hear that.

The full paper is a surprisingly good read; if you're looking for something to flick through on an e-reader over the weekend, why not give it a go?

Spam, spam, spam, spam, spam, spam, spam, spam, lovely spam, wonderful spam. Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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Inside Big Ben: why the world’s most famous clock will soon lose its bong

Every now and then, even the most famous of clocks need a bit of care.

London is soon going to lose one of its most familiar sounds when the world-famous Big Ben falls silent for repairs. The “bonging” chimes that have marked the passing of time for Londoners since 1859 will fall silent for months beginning in 2017 as part of a three-year £29m conservation project.

Of course, “Big Ben” is the nickname of the Great Bell and the bell itself is not in bad shape – even though it does have a huge crack in it.

The bell weighs nearly 14 tonnes and it cracked in 1859 when it was first bonged with a hammer that was way too heavy.

The crack was never repaired. Instead the bell was rotated one eighth of a turn and a lighter (200kg) hammer was installed. The cracked bell has a characteristic sound which we have all grown to love.

Big Ben strikes. UK Parliament.

Instead, it is the Elizabeth Tower (1859) and the clock mechanism (1854), designed by Denison and Airy, that need attention.

Any building or machine needs regular maintenance – we paint our doors and windows when they need it and we repair or replace our cars quite routinely. It is convenient to choose a day when we’re out of the house to paint the doors, or when we don’t need the car to repair the brakes. But a clock just doesn’t stop – especially not a clock as iconic as the Great Clock at the Palace of Westminster.

Repairs to the tower are long overdue. There is corrosion damage to the cast iron roof and to the belfry structure which keeps the bells in place. There is water damage to the masonry and condensation problems will be addressed, too. There are plumbing and electrical works to be done for a lift to be installed in one of the ventilation shafts, toilet facilities and the fitting of low-energy lighting.

Marvel of engineering

The clock mechanism itself is remarkable. In its 162-year history it has only had one major breakdown. In 1976 the speed regulator for the chimes broke and the mechanism sped up to destruction. The resulting damage took months to repair.

The weights that drive the clock are, like the bells and hammers, unimaginably huge. The “drive train” that keeps the pendulum swinging and that turns the hands is driven by a weight of about 100kg. Two other weights that ring the bells are each over a tonne. If any of these weights falls out of control (as in the 1976 incident), they could do a lot of damage.

The pendulum suspension spring is especially critical because it holds up the huge pendulum bob which weighs 321kg. The swinging pendulum releases the “escapement” every two seconds which then turns the hands on the clock’s four faces. If you look very closely, you will see that the minute hand doesn’t move smoothly but it sits still most of the time, only moving on each tick by 1.5cm.

The pendulum swings back and forth 21,600 times a day. That’s nearly 8m times a year, bending the pendulum spring. Like any metal, it has the potential to suffer from fatigue. The pendulum needs to be lifted out of the clock so that the spring can be closely inspected.

The clock derives its remarkable accuracy in part from the temperature compensation which is built into the construction of the pendulum. This was yet another of John Harrison’s genius ideas (you probably know him from longitude fame). He came up with the solution of using metals of differing temperature expansion coefficient so that the pendulum doesn’t change in length as the temperature changes with the seasons.

In the Westminster clock, the pendulum shaft is made of concentric tubes of steel and zinc. A similar construction is described for the clock in Trinity College Cambridge and near perfect temperature compensation can be achieved. But zinc is a ductile metal and the tube deforms with time under the heavy load of the 321kg pendulum bob. This “creeping” will cause the temperature compensation to jam up and become less effective.

So stopping the clock will also be a good opportunity to dismantle the pendulum completely and to check that the zinc tube is sliding freely. This in itself is a few days' work.

What makes it tick

But the truly clever bit of this clock is the escapement. All clocks have one - it’s what makes the clock tick, quite literally. Denison developed his new gravity escapement especially for the Westminster clock. It decouples the driving force of the falling weight from the periodic force that maintains the motion of the pendulum. To this day, the best tower clocks in England use the gravity escapement leading to remarkable accuracy – better even than that of your quartz crystal wrist watch.

In Denison’s gravity escapement, the “tick” is the impact of the “legs” of the escapement colliding with hardened steel seats. Each collision causes microscopic damage which, accumulated over millions of collisions per year, causes wear and tear affecting the accuracy of the clock. It is impossible to inspect the escapement without stopping the clock. Part of the maintenance proposed during this stoppage is a thorough overhaul of the escapement and the other workings of the clock.

The Westminster clock is a remarkable icon for London and for England. For more than 150 years it has reminded us of each hour, tirelessly. That’s what I love about clocks – they seem to carry on without a fuss. But every now and then even the most famous of clocks need a bit of care. After this period of pampering, “Big Ben” ought to be set for another 100 or so years of trouble-free running.

The Conversation

Hugh Hunt is a Reader in Engineering Dynamics and Vibration at the University of Cambridge.

This article was originally published on The Conversation. Read the original article.