Is there any scholarly consensus about the origins of organized crime historically? Do movements such as the Ndrangheta have analogues in the pre-Christian or Medieval world? Or is it a relatively new, post-Industrial kind of thing?
There's no good cut-and-dried answer to what 'the origins of organized crime' are, as it is a phenomenon that sprang up in many places independently. I'm not aware of any consensus as to the very first example of an organized criminal group either, although, as DVK points out, you would have to define what you think would qualify as organized crime.
Certainly many criminal organizations that are still functioning today, such as the Ndrangheta you mention, Cosa Nostra, the Yakuza, the Triads, etc. arose in the late 18th and early 19th centuries at least partially in response to the upheaval brought on by modernization/foreign expansion into their home country. Many of these kinds of groups began as rebellions or citizens' vigilante organizations that slowly transformed into protection rackets once whatever threat that prompted their formation had faded. Most of these organizations distinguished themselves (and still do to some extent) by adhering to a strict system of patronage and hierarchy that is based around traditional customs that were falling by the wayside in regular society.
However, groups that operate along similar lines to what we would call organized crime have been commented on as early as 50 BCE . If you're interested in organized crime in the ancient world, the book DVK mentioned, Organised Crime in Antiquity, might be a good place to start.
I'm not sure about consensus, but there are books on the topic. Example:
Further east, Yakuza originated in 1600s.
More controversially, you could view pretty much any feudal lord as an organized criminal (since your question wasn't terribly specific on how you define organized crime). You have a boss with violent enforcers who collects taxes from people in his area.