An alternative to Pedro's provocative idea: dumping the euro. I know that economists are notorious in making predictions. Still, I think that it is pretty safe to assume that if the Portuguese economy does indeed have another "lost decade" (that is, if it remains stagnated for a prolonged period of time), it is very likely that in 10 years time we will be discussing how and when we will leave the euro. The country will not take another 10 years of low growth, high unemployment and high emigration (which, yes, is back big time) without politicians (and economists) starting to consider this heretic possibility. I know that leaving the euro is risky and costly, but I would not be surprised if this possibility becomes increasingly attractive if stagnation persists. (If it is not us, this is certainly a possibility for Italy or Greece).
Personally, and although I think that there is overwhelming evidence that the euro has been the main culprit (together with the world trade liberalization and the EU's expansion to Eastern Europe) for the current woes, I also do believe that the costs of leaving the euro are probably too high. Also, in the long run, there might be some efficiency gains associated with belonging to a strong currency like the euro. In other words, it might not be worth it to dump the single currency.
Nevertheless, as we all know, not only in the long run we are all dead, but also, in the medium term, if stagnation persists, it is very likely that a populist politician might persuade the electorate that the euro is the root of all our ailments. And, in a scenario of 10-20 "lost" years, who could blame him/her for it?