Europe’s banking union project, initiated in 2012, has had a promising start. But its stated aim of breaking the vicious circle between banks and sovereigns is very far from being achieved. A key bank-sovereign linkage is the euro area’s home-bias problem, namely the fact that the sovereign exposures of many euro-area banks are highly concentrated in the home country, instead of being diversified within the monetary union.
The home-bias problem, in turn, is a key obstacle to the adoption of a European Deposit Insurance Scheme (EDIS), as proposed by the European Commission in late 2015, because of the suspicion that deposits protected by EDIS would be used by banks, under moral suasion from their home country’s government, to excessively increase their purchases of that government’s debt. In turn, the absence of a full EDIS is one of the banking union’s greatest weaknesses because deposits are not protected uniformly.
There is therefore a strong policy case for the simultaneous consideration of EDIS and of a regulatory instrument targeted at reducing highly concentrated sovereign exposures. The adoption of one of these two reforms without the other is both unlikely and arguably undesirable.
To address the home-bias problem, a general and mandatory (Pillar 1) regulatory requirement is necessary. It should focus on sovereign concentration risk rather than sovereign credit risk, constraining only large exposures as opposed to the risk-weighting of all sovereign assets (the latter might also be envisaged, but on the condition of a global consensus and thus presumably at a later stage). Because the home-bias problem is unique to the euro area, the new requirement should only be binding for the euro-area sovereign exposures of euro-area banks.
This paper outlines a workable design for a Sovereign Concentration Charges Regulation (SCCR) as new EU legislation to be adopted as a complement of EDIS. The SCCR would add sovereign exposures above a certain threshold (defined as a ratio to Tier-1 capital), weighted by a coefficient (sovereign concentration charge) that increases with the exposure ratio, to risk-weighted assets in the capital ratio’s denominator. The charges for concentrated sovereign exposures to different euro-area countries would add up.
While the banks’ behavioural response to the new regime is impossible to predict with certainty, it is expected that most banks will respond to the introduction of the SCCR by diversifying their sovereign exposures away from their current home bias, but leaving them largely unchanged in euro-area aggregate. If so, the reform will neither materially impact banks’ prudential ratios nor entail any material costs.
The adoption of the proposed SCCR together with a full EDIS, ideally complemented by other reforms to increase risk-sharing and enhance market discipline in the banking policy framework, would significantly reduce bank-sovereign linkages and thus strengthen the banking union, foster greater EU financial integration, and increase financial stability for each member state and for the European Union as a whole.