Britain is vying for the award for the most unsuccessful currency depreciation in history. More than a year after it began, the U.K. has nothing but inflation to show for the pound’s plunge.

Net international trade subtracted 0.9 percentage points from year-over-year GDP growth in the third quarter. The monthly trade deficit oscillates wildly, but has remained on a deteriorating trend. Volumes of goods exports have flatlined, while volumes of goods imports have surged, reaching an all-time high in November despite a 10% year-over-year jump in prices.

The woeful export performance is largely explained by exporters’ response to the drop in the pound. Rather than seeking market-share gains by allowing the prices they charge in foreign currencies to fall, they have hiked prices in terms of pounds to cover the increased cost of imported components and in pursuit of wider margins. The price of goods exported was nearly 14% higher in November than a year previously, so foreign-currency prices have fallen by an average of only 4%. The competitiveness of U.K. exports in global markets, therefore, has improved only marginally.

Exports will pick up meaningfully only when new firms enter the market to compete with and undercut existing exporters. But uncertainty about the Brexit process likely means that this will be a slow and tentative process. Who would invest to export now, when Prime Minister Theresa May threatens to fall back on World Trade Organization rules for trade with Europe if her Brexit demands aren’t met? Without preferential access to Europe’s single market, Britain’s exports to the European Union would be subject to tariffs averaging 5% and burdensome customs checks.

The economy’s failure to wean itself off imports is even more striking. The situation might improve with time. Contractual obligations may have prevented many consumers of imports from switching to domestically produced alternatives immediately after the pound’s decline. But the degree of import substitution is likely to be very modest even in the long run. Import prices rose by 20% more than domestic prices between 2007 and 2012, primarily in response to the pound’s 25% depreciation during the financial crisis. The volume of imports as a share of GDP was higher by the end of this period than at the start.