What is the main idea of this passage? [br] [originaltext]A libertarian think t

A libertarian think tank, reckon that eliminating all travel visas to the United States would add between $90 billion and $123 billion in annual tourist spending. By one estimate, introducing visa restrictions can lower trade and foreign direct investment between a pair of countries by as much as 25% .

More than 7,000 years ago, people living in the Middle East discovered that they could ferment grapes to make wine. As with wine, the processing of coffee beans and cacao, used to make chocolate, also requires some fermentation. But new research shows that coffee and cacao yeasts are far more genetically diverse than wine strains. This opens up the intriguing possibility of imparting entirely new tastes to the territory of coffee and chocolate.