The modest pace of the U.S. economic recovery has a silver lining, as the expansion shows signs of lasting almost twice as long as average.

Four years into the upswing, the economy isn't seeing many of the excesses that often presage the start of contractions. Inflation is slowing, not quickening. Household debt is shrinking, not expanding. The labor market is slack, not tight.

Pent-up demand also bodes well for the longevity of the recovery, which has averaged annual growth of about 2 percent since its start in June 2009. Confronted by elevated unemployment and a depressed housing market, Americans put off forming families, buying homes and acquiring cars. Now, with house prices rising and payrolls expanding more rapidly, their behavior is changing.

"The current expansion can continue another four to five years," said Robert Gordon, a professor at Northwestern University in Evanston, Illinois, who's a member of the National Bureau of Economic Research committee that determines when recessions begin and end.

That would make this upswing the second longest on record, behind only the 10-year period that spanned the 1990s. The average since the end of World War II is just shy of five years, at 58 months.

Reflecting the slow, steady pace of the recovery, payrolls rose 175,000 last month, in line with the average over the past year, Labor Department figures released on June 7 showed.

David Fuller's view The US economy's growth rate is in line with the aftermath of credit crisis recessions. Economic evidence previously cited by Fullermoney states that it takes at least 5 to 7 years before GDP growth returns to what most commentators would describe as normal. If we take the end of 2008 as the approximate nadir for the USA's economic contraction, it is currently in the 6th month of the 5th year of this process.

On a global comparative basis, the US economy has two distinct advantages during this recovery phase and beyond.

1) Technology - The US is experiencing a resurgence in its pace of technological development. Powerful corporate Autonomies are at the forefront of this innovative process but they are also assisted by American universities and the US Government. Moreover, the entrepreneurial and democratic USA remains a magnet for global talent.

2) Energy costs - Thanks to private industry and cutting-edge experience in the extraction of fossil fuels, the USA was the first country to develop an effective technology for extracting shale gas and oil. While this process remains controversial, not least given the debate over fossil fuels versus so-called green energy, fracking technology has considerably lowered energy costs in the USA relative to other large industrialised economies. This has made the USA more competitive and its increased use of natural gas has lowered the country's atmospheric pollution.

These two developments have been beneficial for the US stock market and should remain so over the longer term. However, the bull market to date has discounted gradual economic recovery and the growth in corporate profits. Both have been considerably helped by massive quantitative easing (QE) from the Federal Reserve. Anticipation of a reduction in the amount of monthly QE, and its eventual removal as the US economy continues to recover, will cause some stock market turbulence over the lengthy medium term.