There were two big shifts in global markets in the second half of 2014 that looked likely to shape how the American economy would perform in 2015.

Oil prices plummeted last year, leading to cheaper gasoline — good news for American consumers and companies like airlines and shipping firms that are heavy fuel users. Meanwhile, the dollar soared on global currency markets, making life more difficult for exporters who faced higher costs relative to global competitors.

The giant question for the economy in 2015 was which of these forces would prove more powerful. The bad news is that so far, the strong dollar is winning.

Consider a brief list of companies that have reported dollar-related financial struggles in the last few days alone. Household-name companies like Procter & Gamble, 3M and General Electric, among many others, have reported hits to their profitability owing to the rising dollar. First-quarter earnings of publicly traded companies are on track to decline 3.3 percent compared with a year earlier, according to FactSet, which would be the first annual drop since 2012 and the largest since the financial crisis.