The European Commission approximates that a permanent reintroduction of border checks in Europe's passport-free travel area could cost up to EUR 18 billion (USD 20.7 billion) a year, the Times Daily reports.
Some European Union countries, including Germany, have temporarily toughened border controls as hundreds of thousands of people fleeing conflict and poverty have sought asylum.
The Commission said Tuesday that the direct cost of any permanent move could amount to between EUR 5 billion and EUR 18 billion a year.
It would include more expensive road transportation, the impact of delaying and controlling more than 1 billion cross-border trips each year, as well as administrative and customs costs.
The estimate doesn't consider the impact on tourism, lower trade volumes, changes in production chains and the possible undermining of the EU's common visa system.