The dollar came under pressure for the fifth day in row yesterday as further evidence of weakness in the world's largest economy emerged and as a key international body warned that the US economy was running out of steam.
Henry "Hank" Paulson, the US treasury secretary, reiterated on a visit to London that the Bush administration remained wedded to a "strong dollar" but this failed to stem the tide as dealers bet that the long-expected slump in the greenback's value had finally arrived.
Having recovered some lost ground late on Monday, the dollar set a fresh two-year low of just above $1.95 against the pound in hectic trading yesterday. There is widespread speculation that it could soon breach the $2 level - something it has not done for 14 years. It also slid to a 20-month low against the euro of $1.318. The US currency has now shed 11% of its value against the euro this year and 12% against the pound.
In reality, though, the dollar has been falling steadily for four years. On a trade-weighted basis against a basket of other currencies, it has lost nearly 31% of its value as fears over its giant current account deficit drag on the currency.
A big deficit, caused by Americans consuming more goods from abroad than they export, theoretically pushes a currency down until imports become more expensive and exports cheaper, at which point the deficit is reduced. But the dollar has held up because big exporters to the US, such as China, have used their current account surpluses to reinvest in American assets, thus keeping demand for dollars high.
Indeed, the dollar surprised everyone in 2005 by regaining some of the losses of the previous three years and so is still not back to the lows it visited at the end of 2004, in spite of the recent falls.
A weaker dollar means a shopping bonanza for Britons. Airlines and travel firms have seen a surge in bookings as people rush to take advantage of cheap US goods that just got cheaper. The flipside, though, is for British companies such as Jaguar to get hit hard in the American market if prices in dollars rise.
About 10% of British trade is with the United States, so exporters will suffer from the stronger dollar but importers of US goods will see costs fall. Petrol prices at the pump could fall as the world's oil and oil products are priced in dollars.
Mr Paulson, former head of the US investment bank Goldman Sachs, repeated the usual mantra of US treasury secretaries that he favoured a strong dollar. "A strong dollar is clearly in our nation's interest and I feel very good today about the strength of the US economy," he said after addressing the CBI conference in London.
He was upbeat about the US economy in spite of the slowdown in growth and, in particular, the housing market. "We have a healthy economy that is making a successful transition from a rate of growth that earlier in the year was not sustainable to one that is sustainable."
Mr Paulson said again that the US sought greater flexibility from China. The US has long wanted Beijing to let its currency rise against the dollar to remove the artificial advantage that the pegged yuan gives Chinese exporters.
But data out shortly after he spoke showed that the weakness in the dollar might be more home-grown. Orders for durable goods fell unexpectedly sharply, by 8.3% in October from September, driven by big falls in civilian aircraft, computer and electronics orders.
James Knightley, of ING Financial Markets, said: "This perhaps suggests that the US economic slowdown is spreading to the corporate sector." He said the Federal Reserve, which raised rates from 1% in 2004 to 5.25% this year, may cut them again as soon as March.
But Ben Bernanke, Federal Reserve chairman, said in a speech last night that there were still inflationary forces in the US economy and hinted that the Fed may need to raise rates. That dampened hopes for an early rate cut, although Mr Bernanke noted that the weak housing market posed a downside risk to growth.
Data released yesterday showed sales of existing homes rose in October for the first time since February, to an annual rate of 6.24m homes. But the figures also showed that house prices dropped 3.5% on a year earlier - the third straight month of decline and the worst year-on-year fall since records began in 1968.
To compound American woes, the Paris-based Organisation for Economic Cooperation and Development said in its latest outlook that the US economy was slowing and would only grow by 2.4% next year after a downwardly revised prediction of 3.3% for this year.
It blamed the housing market slowdown for the lacklustre US performance but said the rest of the world would march on. Jean-Philippe Cotis, the OECD's chief economist, said: "Rather than a major slowdown, what the world may be facing is a rebalancing of growth across OECD regions."
El dólar estadounidense cayó a su nivel más bajo en 15 años frente a la libra esterlina, lo que se considera un síntoma de los problemas de la economía más grande del mundo.

El dólar ha estado bajando por cinco días consecutivos y el martes (28) alcanzó su valor más bajo. En las cotizaciones del mercado de divisas ahora se necesita US$1,95 para comprar una libra y muy pronto podrían ser $2; US$1,38 para comprar un euro. La moneda estadounidense ha perdido el 11% de su valor contra el euro y el 12% contra la libra esterlina en lo que va corrido del año.

El secretario del Tesoro de los Estados Unidos, Henry Paulson, ha reiterado sin embargo que la administración Bush está comprometida con mantener un dólar fuerte. Sin embargo, sus afirmaciones no lograron convencer al mercado, que le apostaba a una caída del dólar en cualquier momento.

Entre las causas de la debilidad de la moneda norteamericana están el mayor consumo de bienes importados y la baja exportación, lo cual según la teoría económica presiona la divisa hacia la baja para que se abaraten dichos bienes de exportación. El dólar se ha mantenido estable porque las economías asiáticas, que son las mayores exportadoras hacia los Estados Unidos, han reinvertido sus superávit de dólares en activos estadounidenses, manteniendo la demanda por el dólar alta.

El dólar no cayó con respecto a las monedas asiáticas debido a que China pega el yuan al dólar, impidiendo variaciones significativas de la tasa de cambio. Corea del Sur mantuvo su política de intervención de la moneda para protegerse de su dependencia de las exportaciones hacia Estados Unidos.

El efecto de la caída es menor para los Estados Unidos puesto que su deuda está denominada en su propia moneda, además las firmas extranjeras tienen la tendencia a poner los precios en dólares para mantener su proporción del mercado norteamericano. No obstante, si el dólar continuara cayendo, debería haber un reajuste de la balanza comercial conduciendo a mayores exportaciones y menores importaciones. Pero no es claro todavía si la industria norteamericana, golpeada por años de competencia extranjera, pueda reaccionar lo suficientemente rápido a este cambio de condiciones. En caso de que esto ocurriera, la economía estadounidense entraría en una recesión.