I would instead rank (note the spacing):

(1) medicine
(2) law




(3) banking

Bankers are usually retrenched in their mid forties and then have to take up much lower paid second careers like teaching, whereas doctors and lawyers can work till their eighties or even nineties in the same profession, provided if they're not doing surgery, hence their lifetime earnings are much higher.

Renowned psychiatrist Dr. Wong Yip Chong, who passed away at age 82 in August 2011, was earning $3 million a year at age 75 in 2004.

The Straits Times Aug 9, 2011

"Yesterday, Justice Lai rejected Meng Cheong's and Meng Leong's claims that their father was mentally incompetent in December 2004, when he signed the document making Madam Ling the joint owner of the house.

The judge noted that Dr Wong, the 'cash cow' of the Adam Road Hospital he founded, treated 727 patients that month and generated $3 million in income that year; he was also signing complex corporate documents well into 2006."

I cannot imagine a banker still earning $3 million a year at age of 75, unless he owns the bank, which brings me to another point. In the first two professions (medicine and law) you are the employer whereas in banking you are most likely just an employee (unless your family owns the bank).

You get lots of respect being an employer than an employee and it does wonders for your ego, something money cannot buy.