The National Bureau of Economic Research said Monday that although most barometers show improvements in the economy, it would be "premature" to pinpoint the end of a recession based on economic data seen so far.

That assessment came after the group of academic economists met at its Cambridge, Mass., headquarters on Thursday to review mountains of economic data.

The panel looks at figures that make up the nation's gross domestic product, which measures the total value of goods and services produced within the United States. It also reviews incomes, employment and industrial activity.

The economists decided that many of the key economic indicators are "quite preliminary at this time and will be revised in coming months," NBER said. The government often changes its estimates of economic growth, job creation and other important barometers based on more complete information. The panel of academic economists was wary of making a declaration about the end of the recession when key government figures could still be changed.

NBER has already pinpointed the start date of the recession as December 2007, a determination it reaffirmed on Monday. Many private economists believed the recession ended in June or July last year. It has been the longest and worst downturn since the 1930s.

The economy started growing again in the second quarter of last year after a record four straight quarters of declines. The economy also has started to generate jobs again - albeit at a sluggish pace.

The NBER normally takes its time in declaring a recession has started or ended.

For instance, the NBER announced in December 2008 that the recession had actually started one year earlier - in December 2007.

Similarly, it declared in July 2003 that the 2001 recession was over. When did it actually end? Twenty months earlier - in November 2001.

Its determination is of interest to economic historians - and political leaders. Recession that occur on their watch pose political risks.

In President George W. Bush's eight years in office, the United States fell into two recessions. The first started in March 2001 and ended that November. The second started in December 2007; its end date is pending the NBER's determination.

The timing of the NBER's decision likely means little to ordinary Americans now muddling through a sluggish economic recovery and weak jobs market.

Many will continue to struggle. Unemployment usually keeps rising well after a recession ends. After the 2001 recession, for instance, unemployment didn't peak until June 2003 - 19 months later.

Meanwhile, the Obama administration vowed on Monday to push for even tougher US financial regulation reform, as legislation heads for the Senate floor as soon as next week.

The White House proposal to clamp down on banks' risky activities shocked global markets when it was announced earlier this year, but there are signs the ideas may be watered down as other governments push forward with post-crisis clampdowns.

The bill now inching forward in the Senate would prohibit banks from proprietary trading and owning a hedge fund or private equity business, though it leaves the door open for regulators to weaken it in final implementation.

Invoking the 2007-2009 financial crisis in an appeal for action, US Deputy Treasury Secretary Neal Wolin said: "We will fight hard against any effort to weaken that legislation, and we will work to strengthen it further where we can." "We cannot afford to let the memory of the crisis fade without taking action." The Senate Banking Committee approved wide-ranging Democratic legislation last month that proposes new rules for derivatives, consumer financial products and a way to ensure that no financial firm is "too big to fail." The measure got no votes of support from Republicans on the committee.

Democrats are working to win enough support to ensure full Senate passage, betting that public anger over Wall Street's meltdown and taxpayer bailouts will win over some Republicans ahead of November congressional elections.

That political calculation is not lost on the Obama administration and top federal regulators, who hope to make use of the small window of time before campaigning takes precedence to push the legislation forward.

President Obama will hold a meeting with congressional Republicans and Democrats on Wednesday to discuss financial reforms. He has moved the issue to the top of his priority list since winning passage of healthcare reform last month.

G20 leaders and the International Monetary Fund urged governments last month to redouble efforts in tightening up financial rules as some countries lag in curbing bank pay.

The G20's steering countries said in a letter to all group members that governments must recommit and deliver on reforms they agreed to at a summit on the financial crisis in Pittsburgh last September.

Obama first proposed measures to tighten financial oversight in mid-2009. The House of Representatives approved a bill in December. But the full Senate has yet to act, more than two years since the meltdown of former Wall Street giant Bear Stearns ushered in a crisis that led to massive bailouts.

Speaking at the same conference as Wolin, Federal Deposit Insurance Corp. Chairman Sheila Bair said: "When economic conditions return to normal, risk aversion on the part of investors will decline and risk-taking by banks will return ... Unless we act now on financial reform, we could soon be planting the seeds of the next crisis." The Senate's bill also includes provisions to make corporate boards more accountable by giving shareholders a non-binding vote on executive compensation and a way to influence the composition of a corporate board - an idea abhorred by key Republicans and the most influential US business groups.

The US Securities and Exchange Commission is proposing ways to make it easier and cheaper for shareholders to nominate board directors, anyway, though it has yet to adopt final rules. UK investors can nominate corporate directors.

"Long-term shareholders meeting reasonable ownership thresholds should have the ability to hold board members accountable by proposing alternatives and making their voices heard," Wolin said.

Bair defended her agency's move to clamp down on excessive banker pay and said financial stability is at stake. The FDIC has issued a preliminary proposal to make banks with riskier compensation schemes pay more for deposit insurance.

"The stability of our financial system requires that the interests of management be aligned with all financial stakeholders in the firm - including debt and equity holders - in order to prevent the type of excessive risk-taking that led to this crisis," Bair said.