I’ve been enjoying Slate’s “Green Lantern” feed:

A 1992 study from Franklin Associates estimated that producing a year’s supply of disposables, which are composed largely of plastic, consumes roughly 6,900 megajoules of energy, vs. around 1,400 megajoules for a year’s supply of cloth diapers. Yet the study concluded that cloth ended up being 39 percent more energy-intensive overall, given the electricity needed to wash load after load of dirty diapers.

That conclusion is now woefully outdated, however, given the major advances that have occurred in washing-machine efficiency (PDF). For a washing machine made in 1985, an 11-pound load of cottons washed in warm water used up 1.68 kilowatt hours of electricity and 34 gallons of water; for a machine made two decades later, the relevant figures are just 0.95 kilowatt hours and 12 gallons.

A 2005 study (PDF) by Britain’s Environment Agency took into account some of these technological advances. In making their calculations regarding cloth diapers, the study’s authors used average energy-consumption figures for machines made in 1997. They concluded that there was “no significant difference” between the environmental impact of cloth and disposable diapers. Keeping a child clad in home-laundered cloth diapers for 2.5 years emitted 1,232 pounds of carbon dioxide equivalent, vs. 1,380 pounds for disposable diapers.

So there. Also, are Priuses actually worse for the environment than Hummers? (No: but the source of the urban myth is interesting.) And, are mechanical dishwashers bad for the planet? No they aren’t:

More than 100 Europeans were observed cleaning a dozen full place-settings by hand. The German researchers found that the average hand-washer is quite the wastrel, using 27.2 gallons of water, which requires 2.5 kWh of electricity to heat. (The most careless hand-washers were Spanish and Portuguese, while the most economical were German.) An ultra-efficient machine, by contrast, used only between 3.96 and 5.81 gallons of water, and between 1 and 2 kWh of electricity.Advantage, technology. But if you read the German study carefully, you’ll see that the best hand-washers came close to matching the machine’s performance.

The feed is here.

Last week I mused about whether people in general were saving enough for retirement. (The answer: as far as we can tell, most people are.) This week I have decided to take on a far more important question: am I saving enough for retirement?

Apparently this activity is called “retirement planning”, which strikes me as a silly phrase given the imponderables involved.

Saving for retirement is usually posed as a problem of willpower: foolish, impatient people save too little and doom themselves to an old age devoid of Caribbean cruises. The real problem is not lack of willpower but lack of omniscience.

Hip kid that I am, I started my planning by opening up a spreadsheet. The next steps would have been to project the growth rate of my income, monthly savings, the path of inflation, the return on my growing savings pot, and (eventually) the likely annuity rate on retirement.

The remainder of the column can be read here. Please post comments below. 

I am about to be married, and have no doubts about the relationship. But there is one nagging worry: my fiance co-owns a condo overlooking the Pacific Ocean near San Francisco – with an ex-girlfriend, who lives next door to it. She is not in a position to buy him out of his investment, and although they rent it out, the mortgage is steep. I believe the condo is an investment specific to the former relationship and would like it divested – but the housing market is a shambles.
Mary

Dear Mary,

While I sympathise with your problem, I must correct you. A relationship-specific investment is one that is worth more within a relationship than outside it, such as a set of wedding photos. The condo is not relationship-specific, just unprofitable and illiquid.

The condo can therefore be disposed of without destroying value – but not, it seems, by either side buying the other side out.

If your fiance sold his share to a stranger, he’d sell at a loss. But in truth, the loss has already happened; his reluctance to sell suggests he’s pig-headed as well as an incompetent investor.

So I recommend that you buy out your fiance’s share, at a fire-sale price. Subsequent negotiations about the condo would then be between you and the ex. Should your marriage work out, you can share the profits with your fiance. And if not, at least you will have prearranged some compensation.

Questions to economist@ft.com

Earlier this year, I wrote about the sudden rediscovery of the idea that prizes might be a good alternative to grants or patents as a way of promoting innovation:

In an ideal world, prizes could replace patents. Instead of offering a patent for an innovation, the government could offer a prize. The inventor would pocket the prize but would not be allowed to exploit any monopoly power, so the innovation would be freely available to use in products for poor consumers – cheap drugs for Africa, for instance – and, importantly, in further innovations. But to explain that idea is to see its limitations. How could the government know enough about the costs and benefits – and even the very possibility – of an innovation to put a price tag on it and write the terms of reference for a prize competition? For this reason it is hard to see prizes replacing patents in most cases. But it is not impossible.

The modern heir to 18th-century prizes for canning, water turbines and finding longitude at sea is the advanced market commitment for vaccines for the poor: the goal is clear, the costs and benefits can be guessed at, and the quasi-prize nudges the patent system to one side with a prize contract that respects the patent but, in exchange for a large subsidy, radically constricts the holder’s right to exploit it.

At the time I wrote the piece, I wish I had seen this gorgeous list of historical prizes:

Napoleon Sugar Beet Prize (1810)
In 1810, facing blockade of its ports, Napoleon offered a large prizefor the best method of extracting sugar from beets. The prize was part of a large set of national incentives and mandates to stimulate the production of sugar from beets.

Art of Piercing or Boring Artesian Wells (1818)
Similar in purpose to the 1797 book on Elkington’s methods of drainage, in 1818, the Society for the Encouragement of National Industry in France offered a reward of 3,000 francs for “the best manual, or practical and elementary instructions upon the art of piercing or boring Artesian wells with the miner’s or fountaineer’s augur, from 25 metres (82 feet), to 100 metres (328 feet) depth, and deeper if possible.” The award was given by the Society in 1821 to Mr. Gamier, for an important and useful discussion of the use of Artesian wells employed for the discharge of foul and infected water.

Wisconsin Prize for Mechanical Substitute for Horses and Other Animals (1875)
In 1875, the Wisconsin legislature passed an act authorizing the payment of a $10,000 bounty to “any citizen of Wisconsin, who shall invent, and after five years continued trial and use, shall produce a machine propelled by steam or other motive agent, which shall be a cheap and practical substitute for the use of horses, and other animals on the highway and farm.” The law was amended twice in the next two years, with the final 1877 version eliminating the requirement for “five years continued trial and use,” while adding specific requirements for winning the prize. Contestants with machines that could operate in both forward and reverse were required to complete a 200-mile route at “not less than five miles per hour working time,” and to perform certain functions, such as plowing and pulling loaded wagons. Trials were conducted in 1878 and ended in controversy when one of the judges refused to grant the full prize money to a contestant many observers thought had satisfied the contest rules. Subsequently, two crews split part of the prize money.

Then there’s:

Highland and Agricultural Society of Edinburgh Reaper Prize (1826)

Apple and Pear Prize (1826)

Substitute for Guano (1852)

Napoleon III Margarine Prize (1869)

French Prize Competition in Irrigation Practice (1874)

Italian Prize Competition in Irrigation Practice (1879)

Soviet Committee for Invention Authorship Certificates (1931)

Australian Film Bounty (1933)

Soviet Rewards for Aircraft Design (1946,7)

Burkina Faso Innovation Prizes (1994)

Don’t tell me you’re not curious. Here is the source; Alex Tabarrok pointed me to it some time ago.

Ray Fisman in Slate thinks they are:

A generation later, parents are more worried than ever about making sure their kids can compete in today’s high-tech world, and the growing digital divide is a subject of great concern for educators and policymakers. Federal subsidies in the United States provide billions of dollars for computer access in schools and libraries, and billions more may soon be spent in the developing world through programs such as One Laptop per Child. But even OLPC’s $100 laptop comes loaded with more distractions than my PET ever had. So will kids use these subsidized computing resources to prepare for the demands of the 21^st-century job market? Or do computers just serve as a 21^st-century substitute for that more venerable time-waster—the television?

New research by economists Ofer Malamud and Cristian Pop-Eleches provides an answer: For many kids, computers are indeed more of a distraction than a learning opportunity. The two researchers surveyed households that applied to Euro 200, a voucher distribution program in Romania designed to help poor households defray the cost of buying a computer for their children. It turns out that kids in households lucky enough to get computer vouchers spent a lot less time watching TV—but that’s where the good news ends. “Vouchered” kids also spent less time doing homework, got lower grades, and reported lower educational aspirations than the “unvouchered” kids.

I’d back computers over television any day, but Fisman’s discussion is thoughtful; do read the whole thing. It also echoes this Dear Economist answer:

Previous researchers have struggled to establish a causal link between exam results and time spent studying. That is not a surprise. Bright students might work harder because they enjoy the work. Or failing students might cram to rescue their grades. Untangling the statistics seems impossible.

Yet the puzzle has been resolved by Todd Stinebrickner, an economist, and his father, mathematician Ralph Stinebrickner. Equipped with detailed time-use questionnaires, they looked at students who were randomly assigned a room-mate with a games console. Neither the students nor their room-mates differed in, say, initial test score, time spent boozing, or sleeping. But students whose room-mates had video games spent less time studying and more playing Final Fantasy XII. Pure chance – the assignment of a room-mate – seems to affect time spent studying, and no other important decisions. And yes, the grades did suffer.

The question and full answer can be read here.

My colleague Lucy Kellaway has without apparent effort highlighted a profound point: statistical data is only ever an indirect summary of the true state of the world.

…as The Beatles pointed out, money can’t buy you love. Or rather, money doesn’t make you tick “strongly agree” when someone comes around with a clipboard asking if you are happy at work.

At the weekend, I wrote:

The economist Erik Hurst has recently calculated that while most American households do cut back on spending after retiring, that does not literally mean tightening their belts: the cutbacks mean spending less on commuting and work clothes. Spending on food also falls, but the retirees eat just as well: they simply spend more of their plentiful leisure time cooking at home. Spending on entertainment and donations to charity increase. No sign there of a penurious dotage.

An admired analysis of retirement saving was published in 2006 in the Journal of Political Economy by John Karl Scholz and two colleagues. They concluded that more than 80 per cent of Americans seemed to be on track to retire with enough money in the bank; the remainder were mostly not far short of sensible savings.

In other words, while government and corporate pension provision may lack credibility, personal pension provision seems to be just fine.

Now I’ve received an email from Martin Weale, director of the National Institute for Economic and Social Research. He is not so sanguine, and not convinced by Scholz et al:

The US study makes two questionable assumptions which could be regarded as biasing its findings. First of all, it assumes that people’s life expectancies are defined by 2002 mortality rates. There is no provision for rising life expectancy. Secondly, it is assumed that DB schemes continue in existence. In the UK the ending of DB schemes has been associated with reductions in employers’ and therefore total contributions. Some people who had planned on the basis of continuing DB schemes in 2002 would now find they have not been saving enough.
There is a third point over the definition of savings adequacy. The study assumes that housing wealth is available to fund retirement. In one sense this is true. However, housing wealth includes the value of land which has increased sharply in price. Society as a whole cannot finance its retirement out of rising land prices, except by imposing an extra burden on future generations. Thus financing retirement out of rising land prices is much like doing so by issuing national debt. If the overall question of adquacy of national saving is explored then the effects of rising land prices have to be left out of the equation. On that basis the United Kingdom currently has a substantial savings shortfall, and it is in considerably a worse position than France and Spain.

Martin Weale’s own paper is here; he concludes that the UK is short of savings.

John Hegley once wrote a poem about accidentally ending up with another boy’s school cap - John Hegarty, a boy with “a name like mine and a cap like mine”. My John Hegarty is Tim Harcourt, chief economist of the Australian Trade Commission, an export-promotion body, and author of “The Airport Economist”, which has just crossed my desk.

I think it will only be published in Australia, which makes sense - it’s very much written with the Australian entrepreneur in mind, but that said, very engaging and (as the title implies), some serious air miles went into the production of this book.

Seth Godin’s email checklist:

1 Is it going to just one person? (If yes, jump to #10)
2 Since it’s going to a group, have I thought about who is on my list?
3 Are they blind copied?
4 Did every person on the list really and truly opt in? Not like sort of, but really ask for it?
5 So that means that if I didn’t send it to them, they’d complain about not getting it?
6 See #5. If they wouldn’t complain, take them off!
7 That means, for example, that sending bulk email to a list of bloggers just cause they have blogs is not okay.
…
10 Have I corresponded with this person before?
11 Really? They’ve written back? (if no, reconsider email)…

The list goes on to 36 and almost all of the advice looks good to me.

Beyond the practicality of the checklist, it raised a question in my mind. Some of Seth’s advice was routinely flouted in the early days of mass email (I’m thinking 1995-1999). For instance, many people forwarded jokes and virus warnings. These days they are rare, especially as a proportion of all the email that is sent. Other advice (such as, “don’t admonish people not to print this email”) would have been superfluous ten years ago and is now very widely ignored.
So my question is, what determines why some bad email habits die out and others thrive and multiply? Or is this just the unpredictable outcome of a mysterious process of evolution?

Here’s the conventional wisdom on pensions: you’re a weak-willed and short-sighted fool who isn’t saving enough, and as a result you will spend your retirement in poverty. The US press is loaded with hand-wringing on the subject – largely, although not exclusively, based on “research” from companies who sell pensions and investments. In the UK, the definitive statement was made by Adair Turner’s Pension Commission in 2004: “Most people do not make rational decisions about long-term savings without encouragement and advice.” Ouch.

The sense of impending doom has been deepened by the realisation that both corporate pension schemes and implicit pension promises from governments may have too little cash behind them. That may be true, but it is only indirectly relevant to the question of personal pension saving.

One of the results of this nervousness has been a search for ways to encourage people to save more: tax breaks and enrolment by default, for example.

But look more closely, and it is far from obvious that there is a serious and generalised problem with personal pension saving. It’s hard to say for sure, partly because the future is unknown and partly because it’s hard to say exactly how much money should be in a sensibly funded pension. For example, if someone is making £60,000 a year, what pension income would count as sensible? £75,000 would probably be excessive – but what about medical and long-term care costs? £25,000 a year seems low, but many people get by happily on less.

The remainder of the column can be read here. Please post comments below.