here’s one. it’s a paper from microsoft research researching why so many scammers say they are from nigeria, but the same premise applies:
Far-fetched tales of West African riches strike most as comical. Our analysis suggests that is an advantage to the attacker, not a disadvantage. Since his attack has a low density of victims the Nigerian scammer has an over-riding need to reduce false positives. By sending an email that repels all but the most gullible the scammer gets the most promising marks to self-select, and tilts the true to false positive ratio in his favor.








interesting conclusion, maybe you should publish? you seem to have more info than they did ten years ago.