One of the biggest economic fallacies is the belief that devaluing a currency is the path to economic growth. This mercantilist argument is seen everywhere by all sides of the political spectrum. The argument is that by devaluing its domestic currency, a country will boost exports and reduce imports. Domestic companies will be able to better compete both at home and abroad. Thus, they will expand production and hire more people. Typically, they argue that the only downside is that travelers visiting foreign countries will be faced with higher prices.
I would like to add a few more negative consequences to the devaluation idea. First, all imports will become more expensive. And not only imports, but all exportable goods will become more expensive. Thus, even if the economy produces a surplus of oil, coal, food, cars, etc. - all of these goods can be exported. If they can be exported, and the local currency is devalued, then companies are more likely to export these goods rather than sell them in the domestic economy. This will lower the supply and thus raise the price of all exportable goods.
Higher prices for imports and exportable goods hurt the local economy in two ways. First, companies that have these goods as part of their costs will see their costs rise. If a firm's cost rise, then all else being equal, the firm will reduce production compared to what they would have done without the rise in costs. Now the devaluation supporter will argue that the firm's sales will increase, but this will not be true of all firms. Some firms such as restaurants will see their costs of food go up, and since they do not compete with foreign entities, then they will not gain any benefit from devaluation. Other firms like airlines or computer manufacturers will see costs go up and possibly sales go up. But how can we be sure that the increase in sales will offset the increase in costs? How can the supporters of devaluation know that the overall benefits will exceed the overall costs? I don't believe there is any way to know for sure. Below, however, we will see some regressions testing to see whether countries benefit from devaluation.