...Grexit would be a significant shock to the eurozone, disproving the irreversibility of euro membership, sparking financial market volatility and denting economic confidence. But it is unlikely to trigger a systemic crisis like that seen in 2012, or another country's rapid exit. All else being equal, the risks of a given country leaving would be higher but this might spur strengthening of eurozone institutions. In the medium term, there would be greater exit risk for countries where political commitment to reform weakened....