Facebook Inc.’s 2016 earnings got a boost of more than $900 million from an accounting change—and the same change could help lift earnings at other technology companies.

Facebook said Wednesday after the market closed that its full-year earnings reflected a $934 million reduction in its income-tax provision, including $214 million in the fourth quarter, from a new rule affecting the accounting for stock payments to employees. The tax reductions contributed to big increases in the company’s fourth-quarter and 2016 net income.

...