Here are the overriding facts that are unlikely to change without a change in policy:
1. Greece is in the grips of an economic and humanitarian crisis. In fact, unless there is a substantial change in course, it runs the risk of becoming a failed state altogether.
2. Greek sovereign debt is not payable. Its society will collapse first.
3. There does not exist the political will in Europe for a transfer union that mutualizes the obligations and needs of Greece on a permanent basis. This is in contrast, for instance, to the United States, in which most sovereign debt is mutualized and interstate transfers occur on a routine basis. A transfer union might be a first-best solution in Europe, but it is politically infeasible.
4. Under current circumstances, Grexit would be experienced in Greece, and possibly through much of Europe, as a catastrophe. A hurriedly introduced drachma would be unanchored, and the redenomination of contracts would be chaotic and disruptive of ordinary business. Greek savings would either flee or be largely wiped out, with dangerous political consequences.
5. Nevertheless, Greece was a poor candidate to enter the eurozone when it did and is a poor candidate to remain in the zone today. Above all, it lacks a sufficiently large, diversified and productive export sector to permit growth under a fixed exchange rate without the accumulation of unsustainable current account imbalances.
6. Greece is a small country from an economic perspective, and its political-economic challenges are unique. Properly managed, Grexit does not need to lead to similar policies for larger countries, like Spain and Italy, whose imbalances are not structural in Greece’s sense.
7. Finally, the political evolution of the antagonism between Greece and the creditor countries is pernicious. The nationalist rhetoric of victimization and resentment, wherever it occurs, is a proven threat to peace and international cooperation. This alone should be reason enough to change course.
At present Grexit exists as a threat wielded by both sides to extract concessions from the other. It is a threat to the extent it would be catastrophic, either for Greece in the form of economic chaos or for Europe in the form of contagion. Nevertheless, properly prepared, Grexit could be a mutually beneficial solution.
What would proper preparation look like? Here is the sketch of a plan:
First, Grexit would be proposed as one element in a comprehensive solution whose political premise is substantial generosity on the part of the creditor countries with the understanding that this is strictly a one-time event.
Second, as a precondition for Grexit, the existing sovereign debt of Greece would be largely written off, with a residual obligation (under 50% of GDP) clearly consistent with favorable growth prospects. This may require Europe to assume some degree of obligation for Greece’s debts to the IMF.
Third, the ECB would provide temporary euro reserves to the Bank of Greece in order to support a stable transition back to the drachma. This could take the form of a swap line which would be resolved and terminated by some target date several years after Greece’s exit from the euro.
Fourth, the mandatory redenomination of contracts and financial assets whose payment streams would be in drachmas would be permitted to occur over a suitable time frame, such as a year. In other words, just as with eurozone accession, eurozone exit would involve a period of dual currencies with strict parity in order to facilitate orderly redenomination. The commitment of the ECB to support the drachma well beyond the period of redenomination would underwrite this process.
The end result would be an economically sovereign Greece and a eurozone no longer obligated to finance it. Both sides would benefit from better conditions for economic growth and reduced political stress. In fact, it is probable that the large-scale economic restructuring needed in Greece can be accomplished only under circumstances of fundamental sovereignty and freedom that allow experiment with deep reforms.
Such a Grexit should be viewed as a solution incorporating goodwill on all sides, whose goal is progress and not punishment. It would not be accompanied by expulsion from the EU or any other retaliatory measure. After a suitable period of time, Greece could reapply for eurozone membership if it chooses without prejudice—either against or for accession.
UPDATE: I have left out perhaps the most difficult aspect of a gracefully managed Grexit, the issuance of new Greek sovereign debt during the dual currency period. The more such debt is issued, the greater is the ECB’s de facto commitment to the drachma. The typical eurozone solution would be to impose an upper bound on Greek deficits over the period, probably adhering to the bright line of the Stability and Growth (sic) Pact, in exchange for drachma support. This would not be ideal, but under the circumstances it is probably necessary for selling the deal. And Greece would always have the option of foregoing the support if it had confidence in its monetary and fiscal space.