If you put Greek total debt in perspective, it’s smaller than that of many other EU nations, including Portugal. And that is as a percentage of gdp. Furthermore most of the remaining Greek debt is held by public sector institutions.

The difference of course is that Greece is being run by The Not Very Serious People. Portugal is often described as the next weakest link in the eurozone, but Portuguese politics are not nearly so…vivid. The amount of fiscal consolidation they have done is more or less accepted by the public. That makes Portugal more likely to survive, and it also makes the EU more willing to bail out Portugal, and extend any bailout if needed.

The performance of Syriza won’t encourage European voters to take chances on other less tested, left-wing parties, and that also militates against contagion.

(In the meantime, I don’t understand why Anglo-American left-wing intellectuals have been egging on the Syriza performance. Even if you think the current mess is mostly Germany’s fault in normative terms, the marginal product of the Syriza government still has been catastrophically negative. It wasn’t long ago that Greek banks were raising fresh equity and were said to have recovered. Here is Krugman’s defense, I find Anders Aslund more persuasive, furthermore Grexit would mean more austerity not less.)

For contagion, here are a few possible problems:

1. If Greece does reasonably well after Grexit, many others will ask why should they not follow suit and that could turn into a self-fulfilling prophecy. I’ll bet against that, but it’s worth mentioning. It also would take a while to develop.

2. As Greece exists, the ECB has to express a strength of commitment to the other debt-ridden nations. Delivering the right message is tricky here, because for legal and public opinion reasons the ECB cannot make the kind of unconditional commitments the Fed can. So markets might become unhappy with the decline in creative ambiguity at the ECB. I believe the ECB can finesse this one — in essence the message “we’ll help any EU government which is more responsible than Syriza” is fairly credible and in fact is already being signaled by the Eurogroup. So I’ll bet against this problem too, but still it could happen.

3. If only for geopolitical and also humanitarian reasons, the EU cannot wash its hands of Greece, even if Greece leaves the EU. But deciding how to deal with Greece might bring considerable disagreements among the remaining eurozone nations, as might the attempt to spell out exit procedures. Festering, emotional issues are not good for dysfunctional political unions, and a lot of the “hold the line” solidarity might melt away with Grexit.

4. There might be a very slow form of contagion as the reversibility of the currency union becomes better and better known and people start seeing it as little more than a currency board arrangement. As with #3, that could become an ongoing problem, still it doesn’t quite seem dramatic enough to produce rapid contagion.

Here is my previous post on the topic. Robin Wigglesworth surveys a variety of differing views on contagion and other short-run effects. I wrote this post last night, so if I am wrong it might already be evident by now.