November's result was down 4.4 per cent from October's 1.4 million TEU, and 2.2 per cent less than November 2006. That made November 2007 the fourth month in a row to show a year-on-year decline. August throughput was down 1.4 per cent, September down 1.9 per cent and October down 3.5 per cent.
"Retailers were managing their inventories very carefully during the holiday shopping season, and their efforts worked well," said NRF vice president Jonathan Gold.
The ports of LA/Long Beach, Oakland, Tacoma, Seattle, New York/New Jersey, Hampton Roads, Charleston, Savannah and Houston handled 1.38 million TEU in November, the most recent month for which complete numbers are available.
Some fear December's spike could be short-lived because it was small year on year and perhaps resulted from a longer post-Thanksgiving shopping season in 2007 compared to a shorter one in 2006.
Massachusetts-based Logistics Management magazine cited Global Insight analyst and Port Tracker author Paul Bingham as saying: "Our estimate that the four-month run of lower year-over-year monthly volume could also be signalling a trough or plateau in the further weakening of the economy and associated import demand.
"These year-to-year increases are small and reflect that the economy is not yet in recession, so there is growth, albeit weak, in demand," he said.
Mr Bingham also noted that results in the first half of 2008 may also be affected by importers building inventories to protect against possible work stoppages arising from west coast longshoremen's contract talks this spring. "Some shippers may hedge," he said.
Port Tracker forecast mixed results for the first quarter, with January expected to register 1.31 million TEU, an increase of 1.8 per cent compared to the same month the previous year. But February, the slowest month of the year, is expected to post a 5.5 per cent year-on-year decrease at 1.24 million TEU. An upturn is expected in March with a year-on-year increase of 6.3 per cent to 1.35 million TEU.
Analysts expect the second quarter to open well with a 1.43 million TEU April strengthening, up 8.1 per cent year on year while May throughput is forecast at 1.44 million TEU, up 4.4 per cent.