Bret Devereaux

I disagree. The historian Charles Bartlett called it a "severe economic crisis", and every financial and economic historian I have read on the subject thought it was a serious financial crisis. Perhaps it takes people with banking experience or knowledge of financial history...

to recognize how familiar the sequence of events were, beginning with years of capital outflows prior to the crisis. At any rate if this were only a minor event, it is hard to imagine why Tiberius, someone not famously liberal with his money, would have made such...

...a large, interest-free, 3-year loan to bankers when loans at the time were rarely extended for more than a few months. This was unprecedented, and was unlikely to be a response to a minor matter.

It was not unprecedented. Tiberius' two immediate predecessors, Julius Caesar and Octavian had made similarly sized donations to either the people of Rome, the public treasury, or both.

Octavian (Augustus) is at pains to point out that he made similarly massive donations to the public (RG 15) and that he bailed out the public treasury no less than four times, at a number significantly greater than what Tiberius spent (RG 17)

I suppose at some point it depends here on what we understand as a major crisis - evidently significant enough to drag in the emperor...but mostly because its consequences were confined to the landholding elite that dominated Roman politics.

My understanding is that the trigger was the insolvency of a major Alexandrian banking house specializing in shipping, and that it affected cities in Greece and Asia minor and may have even been felt as far north as Belgica, which suggests to me that it was pretty widely spread.

Right - and I am asking where that is in the sources or evidence? Dio, Suetonius and Tacitus do not say this. Barlett provides no additional sources in what I can find of his.