6 people died out of 3500 on Diamond Princess. This suggests about 0.17% will die. That's max 10 million worldwide (for comparison, flu killed 500,000 a year). Real numbers will be nowhere near as it won't spread everywhere. If it's twice as bad as flu then that's about a million deaths worldwide (still way less that aids or TB).
The last global crash killed 500,000 in excess cancer deaths alone, and 10,000 in suicides just in the rich countries. Real figures are in the millions and this crash willl be worse. But hard to predict as it would be mitigated by handouts and self-help if people stop fucking obeying.
Deaths from quarantine will be impossible to calculate because most of them will be delayed. People whose purpose in life is lost and they commit slow suicide by drugs, risk-taking, alcohol or crime.
