Economists were surprised by the news that September 11 led to a bigger trade surplus for Canada.

Border delays in the wake of the attacks in the U.S. helped generate a September surplus of $4.7 billion, up by about $800 million over August’s downwardly-revised number.

Economists had expected a narrower reading, and so they remain skeptical of the report. “Little should be made of Canada’s improved surplus position, however, given the distortions surrounding September data and the ongoing evidence of faltering external demand,” says CIBC World Markets. “Contrary to expectations, imports were more clearly affected by the widespread border delays that sprang up in the wake of the 11th.”

Imports plunged 4.6% in the month, as every major category suffered declines. Exports also slipped 1.7% in the month, primarily due to weaker energy prices. All the major energy sub-sectors dropped in September.

“Overall, the 14.2% drop in energy exports saw the energy trade balance contract by nearly $500 million—compared with a $1.3 billion widening in the non-energy balance,” says CIBC.

“Today’s report closed the books on another a disastrous quarter for Canadian trade. Real exports contracted for the fourth straight quarter, declining by an annualized 6.8%. Overall, the slippage in real exports will contribute to negative GDP growth for Q3, while a comparable decline in real imports will likely be offset by reduced business investment in machinery and equipment,” says CIBC.

It notes that while further easing of U.S. interest rates is uncertain, the Bank of Canada still looks set to cut rates by 50 basis points on November 27.