> There is another way to look at this, which is to say that the German economy is really weak, but the weakness of the economy was hidden by the introduction of the euro,

In the meanwhile Germany added 20 million people from a collapsed country/economy...

> which created a huge market for German capital goods, which gave Germany a big export surplus.

Germany had an huge export surplus before, during and after it.

> Germany came out the big winner of the euro, therefore its export industry is strong, therefore industry can still engage in long-term investments in its workers

Germany did that before the Euro and is still doing it.

> and the labor unions in Germany are very strong, so they can force corporations to spend on training programs.

The companies are more than willing to train their workers. No unions necessary.

> Germany does a good job training its workers, and therefore the Germany economy is strong, is probably wrong on at least 2 counts: > 1.) it probably reverses cause and effect

There is no 'cause and effect'. It makes much more sense to model economy as a system with multiple feedback loops.

The education and training systems constantly creates new workers with relatively high skill sets. You can guess the effects from that and you can also easily guess why the companies are doing this.

> 2.) the German economy is not really strong

That would not make any sense to say. 80+ million people, fourth largest economy in the world.