William Hague — Greece does not mark the end of the euro debacle, merely the beginning

Economics has few laws, which is why economic forecasts are so maddeningly unreliable. If it has one law, it is this: that if you fix together some things which naturally vary, such as interest rates and exchange rates, other things, such as unemployment and wages, will vary more instead. And in a single currency zone, which has exactly this effect, you can only get round these problems by paying big subsidies to poorly performing areas, and expecting workers to move in large numbers to better performing ones.… 

Economics has few laws, which is why economic forecasts are so maddeningly unreliable. If it has one law, it is this: that if you fix together some things which naturally vary, such as interest rates and exchange rates, other things, such as unemployment and wages, will vary more instead. And in a single currency zone, which has exactly this effect, you can only get round these problems by paying big subsidies to poorly performing areas, and expecting workers to move in large numbers to better performing ones.… 

In future decades, in the very business school where I spoke in 1998, I believe students will sit down to study the folly of extending a single currency too far. Sad though it will be to see it, their textbook is likely to say that the Greek debacle of 2015 was not the end of the euro crisis, but its real beginning.

The Telegraph

Greece does not mark the end of the euro debacle, merely the beginning

William Hague, British Conservative party leader when the euro was introduced