Why big business is opposed to Brazil’s economic opening

In his first visit to the U.S. as Brazil’s Economy Minister, Paulo Guedes promised investors looking to grab opportunities in Brazil that, beyond assets, they would find a whole different country, with a more open and pro-business economy. However, considering the first three months of the Jair Bolsonaro government, it seems that won’t be an easy promise to deliver.

It is true that the Jair Bolsonaro administration has delivered its pension reform bill in Congress and promoted concession auctions for infrastructure assets, but the devil lies in the details. The plan to put Brazil among the 50 best countries to do business in four years (instead of the current 109th place in the World Bank ranking)—by slashing and simplifying taxes, signing more trade deals, reducing the size of the state and bureaucracy—depends on the administration’s political wing, which doesn’t seem sold on it.

So far, the most emblematic case of Mr. Guedes’ struggle to open up the Brazilian economy concerns protectionist measures on powdered milk. Since 2001, producers from New Zealand and the European Union had to pay a 14-percent anti-dumping tax. The tariff was set to...