President Trump’s tariffs on metals and Chinese goods have cost U.S. businesses and consumers a combined $13 billion in 2018, according to a study released Wednesday.

The analysis, by the market research firm Trade Partnership Worldwide and commissioned by Tariffs Hurt the Heartland, an ad-hoc group of trade associations seeking to roll back the levies, found that U.S. exports sank last year due to retaliatory tariffs set by China and other countries. Overall, exports declined by $15.7 billion, or 14 percent, last year, but exports of products not subject to retaliation increased by $119 billion, about 10 percent, indicating that companies could still sell abroad if the field was level.