gassor
There may be more posts after this.
Given the amount the economy has already contracted and the amount of contraction predicted in your anonymous three year old quote and the almost universal way that economies go after massive recession and currency devaluation, then it would seem highly unlikely that Greece would be anything but booming 3 years after an exit.
Quote is from Wiki, but the study was undertaken by the National Bank of Greece.
Massively rising import prices and recession added to cripplingly high rates of inflation as the govt, short of revenue, and a shrunken financial sector would be forced to print money. I think it is impossible to say how things would go after that, but I think it would take longer than 3 years to have the economy growing rapidly.