Ten years after the collapse of Lehman Brothers, this is where the European banks are

Non-performing loans are one of the main obstacles to bank profitability in Europe. A high level of bad debts increases the amount of liabilities on the balance sheet of a bank. As a result, the lender will have to generate larger profits to offset these liabilities. In recent times, the profitability of European banks has also been put to the test because of a lower interest rate environment, uncertainties surrounding the UK's exit from the European Union.

A report of the European Parliament Since last March, the level of bad debts has decreased somewhat in recent years, from 6.4% in December 2014 to 4.2% at the end of September 2017.

"However, the current level of NPL in the EU is still higher than in other major developed countries," said the report of the European institutions.

Daniel Lacalle, chief economist and chief investment officer at Tressis Gestion, told CNBC by e-mail that there is still a lot of work to be done on non-performing loans.

"European banks have set up core capital and strengthened their balance sheets, but they have not been fast enough and the challenges remain: Non-performing loans in Europe are more than twice as high as the emerging economies at risk remain too high and net profit margins are very low, "he said.

In addition to reducing bad loans, there has also been strong pressure for stricter regulation. Banks have been forced to increase their capital ratios, the European Banking Authority has been set up to oversee lenders and is conducting regular stress tests to make sure banks are strong enough to cope with a crisis.

George Magnus, former chief economist of UBS, told CNBC television on Wednesday that regulation is now more "intrusive", which has made some parts of the financial system safer than there is ten years.

"That said, although I personally think that regulators around the world are much better at detecting and saving individual institutions … the key to solving a systemic financial crisis is the systemic denomination. the economic system that gave rise to this crisis and the previous ones, I do not think we really did that, "he said.