My personal reason is that I have already maxed out 10k Fraud merits. Kidnapping mayor is a slow work towards merit, but I know for a fact that I am working my way towards crime exp AND merits.
Mob boss assassination is better option overall. (about 80% success rate and roughly 0.8x-0.9x the crime exp of arsons) However my personal preference has been mayor kidnapping because it helps me pay off for the daily nerve refill. About 10-12 success per day means free $1 mil per day :)
I don't know but posting in this thread seems to have triggered my crime xp lol. I
achieved 60 nnb way before my expected target. Here is a breakdown (and recap):
Crime | 40-45 | 45-50 | 50-55 | 55-60 |
| Other | 0 | 0 | 26 | 0 |
| Selling Illegal products | 0 | 0 | 11 | 0 |
| Theft | 50 | 91 | 563 | 1670 |
| Drug deals | 0 | 0 | 0 | 0 |
| Computer crimes | 2 | 0 | 404 | 0 |
| Murder | 0 | 0 | 1542 | 242 |
| Fraud crimes | 1521 | 1426 | 805 | 0 |
| Auto theft | 0 | 0 | 38 | 1 |
| Busts | 0 | 100 | 433 | 544 |
| Approx Arsons | 1621 | 1628 | 3559.6 | 3690.8 |
Target | 1,620 | 1,620 | 3,300 | 5,500 |
(Approx Arsons are calculated as 1 Mayor kidnapping = 2x arson, 1 mob boss assassination = 1x arson, 1 bust = 0.2x arson)
These are all incremental counts. I was targeting about 5500 arsons for the nerve bar increase. Achieved the target way sooner than expected.
The only difference I see is that I was involved in 8 successful Plane Hijacking OC (few Planned Robberies and Money Trains too). If the counts alone were to be trusted then I am estimating that every successful Plane HIghjacking gave me about 250 arsons worth of xp.