MATT WAGE was a brilliant, earnest student at Princeton University, a star of the classroom and a deep thinker about his own ethical obligations to the world. His senior thesis won a prize as the year’s best in the philosophy department, and he was accepted for postgraduate study at Oxford University.

Instead, after graduation in 2012, he took a job at an arbitrage trading firm on Wall Street.

You might think that his professor, Peter Singer, the moral philosopher, would disown him as a sellout. Instead, Singer holds him up as a model.

That’s because Wage reasoned that if he took a high-paying job in finance, he could contribute more to charity. Sure enough, he says that in 2013 he donated more than $100,000, roughly half his pretax income.

Wage told me that he plans to remain in finance and donate half his income. One of the major charities Wage gives to is the Against Malaria Foundation, which, by one analyst’s calculation, can save a child’s life on average for each $3,340 donated. All this suggests that Wage may save more lives with his donations than if he had become an aid worker.