Snake River in the shadow of the Grand Tetons, near Jackson Hole, Wyoming: Photo: Grand Teton National Park

Federal Reserve chairman, Ben Bernanke, and European Central Bank president,  Jean-Claude Trichet, will be in Jackson Hole, Wyoming, in the shadow of the majestic Grand Teton mountains,  at the annual Fed symposium for central bankers, which begins today and 3 years after the onset of the credit crunch, the US recovery in particular, is in a fragile state.

The Fed said on Aug 10th that US growth would be slower than expected and it announced it would buy Treasuries to set a $2.05trn floor on its balance sheet and keep interest rates from rising. Trichet said five days earlier that the Eurozone economy was growing faster than anticipated and the ECB was considering phasing out its emergency lending measures.

This week, US economic data confirmed the wobbly recovery with new home sales dipping to a 1963 low and existing home sales falling to a 15-year low. Durable goods data was also week. However, on Wednesday, the Labor Department reported that following last week’s major rise over 500,000, initial unemployment benefit claims fell by more than expected - - 31,000 to 473,000 - -  in the week ended August 21st.

Joseph LaVorgna, chief US economist at Deutsche Bank in New York, cut his estimate for growth this quarter to a 2% annualised rate, down from 4.6%, only two weeks ago.

Stephen Stanley, chief economist at broker-dealer, Pierpont Securities, now forecasts a 2.3% rate of growth, down from a June forecast of 4.1%.

Besides Bernanke's speech today, the Bureau of Economic Analysis will release its second estimate of Q2 US GDP growth, which is expected to be cut to an annualised 1.4% from the first estimate of 2.4%, according to a Bloomberg survey of economists

Mohamed El-Erian, chief executive and co-chief investment officer of the trillion-dollar bond fund manager PIMCO, writing in today's Washington Post says: "Throughout the summer, data signals have become more alarming. Despite all the rhetoric about job creation, unemployment remains stubbornly high and the problem is becoming structural in nature (and, therefore, harder to solve). Consumer credit continues to contract while small companies find it difficult to access new bank lines of credit. Housing activity is falling, and home values are poised for further declines as foreclosures increase. The trade balance has taken an ominous turn, with exports stagnating and imports surging. More Americans are falling through the large holes in the country's safety net."

El-Erian advocates specific measures which would include pro-growth tax reform, housing finance reform, increased infrastructure investments, greater support for education and research, job retraining programs, removal of outdated interstate competition barriers and stronger social safety nets.

CNBC at Jackson Hole: The issues that are keeping the economy off track, with Diane Swonk, Mesirow Financial; Martin Feldstein Harvard University; Richard Berner, Morgan Stanley and CNBC's Steve Liesman:

In bearish times, a black bear straddles a fence in Grand Teton National Park: Photo: Grand Teton National Park

CNBC at Jackson Hole: Many are questioning whether Bernanke and the Fed are running out of ammunition, with Maya MacGuineas, Committee for a Responsible Federal Budget and Philippa Malmgren, Canonbury Group: