BEIJING—Major global stock markets fell Friday ahead of data on U.S. employment costs that might influence Federal Reserve decisions on interest rate hikes to cool inflation. London and Frankfurt opened lower. Tokyo and Seoul advanced while Shanghai and Hong Kong declined. Wall Street futures were mixed after U.S. stocks declined Thursday for a third day as investors tried to figure out how quickly the Fed might raise interest rates. Markets have been volatile since the Fed said in mid-December stimulus that is boosting stock prices would be wound down sooner than planned after inflation spiked to a 39-year high. The Employment Cost Index due out Friday is expected to show the price of American labor rose by about 1.2 percent over the previous quarter in the final three months of 2021. “Another strong wage gain could amplify market expectations” of an unusually large rate hike of 0.5 percentage points as …