The time taken for business to ramp up production when a currency falls means that the cheaper currency does not significantly translate into higher exports, two European Central Bank economists have found.
When a currency rises, however, the impact is much stronger.
A 20% fall in the euro against the dollar between December 2014 and mid-March 2015 has been credited as a key reason for a pick-up in the euro zone economy this year.
But in a report that turns conventional wisdom on its head, research carried out by ECB economists and based on 10 European Union countries between 2001 and 2012 suggested the link between a falling currency and rising exports is not significant.
The paper's findings, published on Tuesday, gel with data showing that, despite the euro fall, euro zone exports growth slowed in the first quarter while imports accelerated.
While this may seem counter-intuitive, the authors of the report argue it is explained by the fact that ramping up export capacity takes time and is expensive, making it hard for companies to benefit from a falling currency.
Conversely, at a time of currency appreciation, companies tend to cut the quantity of goods and services they export rather than lower prices to support sales.
"Prices are rigid downwards and quantities upwards," the authors of the report, Calin-Vlad Demian and Filippo di Mauro, wrote.
They added the link between exchange rate and exports is stronger if the forex move is sharp, that is larger than a 9% depreciation and 12% appreciation.
While the ECB's bond-buying program, announced in January, has the stated objective of bringing inflation close to its target of just below 2%, economists said its main impact has been to knock down the euro.
The currency move has triggered a series of reactions from other central banks, including Switzerland removing a floor on the euro/franc exchange rate and Denmark cutting its policy rate four times since the start of the year.
The Federal Reserve also said in a report last week that a strong dollar was negatively affecting export sales.
(Editing by Jeremy Gaunt)