In 2016, Donald Trump won the US presidential promising to renegotiate PTAs such as the North American Free Trade Agreement (NAFTA) to increase tariffs. In this exercise, we will analyse the impact of those threats on Mexican beer producers. We will assume this market is monopolistic competitive and products are differentiated (i.e. consumers cannot perfectly substitute across beers). Let's assume there are four Mexican firms producing different beers deciding whether to export to the