The Saturday Essay: Just recently, an economists� cliche has been popping up here and there. No great surprise, perhaps, in the circumstances. The wise folk call it �demand destruction�, like nothing so much as a particularly thrilling video game.

Just recently, an economists' cliche has been popping up here and there. No great surprise, perhaps, in the circumstances. The wise folk call it "demand destruction", like nothing so much as a particularly thrilling video game.

It goes something like this. If a great many Americans decide that the price of gas is insupportable, they simply drive less. Self-evidently, demand falls - by approaching one million barrels of oil a day in the United States - and price should follow. Demand Destruction Auto, if you like.

As has been noted often enough, our American friends drove too much and consumed too much of the world's energy to begin with. Their change in habits, by choice or not, is therefore a good thing. So, job done. The market works.

That's the benign version. Yet what if some of our pensioners decide to adopt the same, apparently rational, approach this winter? What if they, too, decide that the price of fuel is intolerable, or actually insupportable, as the cold weather bites? Another good thing? Perhaps not.

You can imagine other examples as "costs are passed on". Some require no imagination. The parents staggered by food price rises who may be tempted to feed themselves, or their children, less well. The school canteens under pressure to stay within their budgets. The tradesman wondering how to keep his van, on which his job depends, on the road. The farmer and fisherman who know too well that supermarkets are rarely keen to absorb someone else's costs.

That, of course, is the great wonder of costs and their passage. It resembles the old children's game with the parcel. When your costs increase, your first, sensible response is to pass them along. When you can do so, you survive. Perhaps you even thrive. But the chain ends always - for apparently there is no alternative - with the consumer-taxpayer. For that economic player, demand and destruction can acquire less positive meanings.

And is there truly no alternative? The government is doing a very good job of conveying that impression. Gordon Brown has abandoned plans to aid the less well-off with fuel vouchers, even as a once-only offer. Meanwhile, we hear that a windfall tax remains "an option", no more. Suddenly vouchers are dismissed as the sort of "short-term gimmicks and giveaways" that Mr Brown has always deplored.

Energy saving is now the big idea.

It is, of course, a very large and important idea. There is no way that it will help many people this winter, however. Mr Brown may have been rebuffed by the EU in his apparent attempt to fund vouchers by increasing the sale of pollution permits to energy companies. Those who need the help may continue to wonder, nevertheless, what the difference is, in principle, between vouchers and the existing winter fuel allowance.

The difference in practice is that the taxpayer supports the latter while the energy companies were expected - many might have said were morally obliged - to pay for the former. They would rather not. Those who would have been helped might then wonder at the 18% increase in dividends paid out last year by the energy "Big Six". Shareholders received £1.64bn from the magnificent revenues that forever need to swell, so we are told, for "investment".

That problem also afflicts the windfall tax. The companies cannot be expected to share their conspicuous recent luck because the government wants their help with a £100bn renewables programme. Perhaps the firms need to be reminded about the nature of luck, and how it can disappear. Mr Brown is also reported to believe that those same companies would merely (here it is again) "pass on" a windfall burden to consumers.

Here's an old-fashioned notion. Why not suggest to the Big Six that any such strategy would result in still another windfall tax until they got the message? If costs can be passed on, they can be passed back. Why not? I forgot: bad for business.

The upshot, in any case, is that present government strategy consists of a minister - Hilary Benn, Environment - denying that he and his colleagues are "caving in", as unions claim, to the Big Six. Mr Benn - a politician or a cartoon: you decide - is another pinning all on energy efficiency as a "long-term" plan. In the short term, we shift for ourselves.

We won't starve, most of us. We will eat, though, with food prices generally rising by 8.3%, meat and fish by 22.9%, and sundry other energy-dependent, often-imported, sterling-vulnerable items topping 40%. Mr Brown is "cautiously optimistic" as to the economy. Does he mean the "real" one, as economists sometimes term daily life?

How much demand for food can be destroyed safely? Quite a bit, in truth. As the Prime Minister himself has observed, we waste too much of the stuff, and import too much of the rest when oil is still over $100 a barrel. Meanwhile, we fail too often to examine how "costs" are passed on in the trade for these essentials. Oil cartels, commodities futures speculators, big supermarket chains and a Bank of England monetary committee paralysed by indecision all play their part.

In the end, however, as with those American drivers, price falls when demand falls and there is not much else a national government in a sophisticated market economy can do about it. That's the tale. So apply those thoughts to the food on your table. Mere temporary economic stresses in a rich country? That's one account.

It does not quite banish the notion, however, that when markets misfire or suffer manipulation some individuals and groups do very well. Others, left holding the parcel, absorb the costs, pick up the bills and suffer according to their place on what might be termed the vulnerability index. They may live within a democratic polity but that is neither, goes the article of undisputed faith, here nor there.

Intervention in the food industry or any other global trade is tricky, it is true. Price controls, for an example, cannot ever be spoken of, lest they make matters worse. The domestic fuel and heating business is another matter. I don't mind wearing a couple of pullovers. Energy efficiency is to be applauded. But neither strategy renders a windfall tax or fuel vouchers illegitimate or impossible.

And if fuel vouchers, why not food vouchers? The answer probably depends on the way in which you regard need and the duties shared, in theory, by business and taxpayer alike. Simply hoping that people will eat 22.9% less, or freeze a bit more, does not seem entirely - here's the word - civilised.

The world has not changed fundamentally within a couple of years. Britain's farmers have had a lousy summer, but elsewhere harvests have been good and all those brief, mysterious shortages have been forgotten. For a snapshot of the energy industries and the costs passing in your direction, meanwhile, note Iran and Venezuela are talking even now of cutting oil production to defend their profits.

The stuff has not run out, not yet. In the west at least there is no shortage, and nor has there been, of food. Someone had better come up with better excuses and better answers. Demand destruction might begin to take on new, more satisfying meanings.