Large multinational companies tend to be less impacted by falling dollar prices because they manufacture at plants around the world and sell components to themselves on an intracompany basis, which tends to minimize currency fluctuations except in extreme cases.

Small companies tend not to have overseas production, so 90 to 100 percent of their overseas sales are exports, Vargo says. “When we look at the data for smaller companies, you can see what I call a greater elasticity of response to dollar changes,” he says.

Vargo notes that while the dollar is down from its March peak levels, it is still higher than in 2008, so the U.S. currency has to remain low for some months before its full impact can be felt.

“When we look at exports over the longer term, when the dollar is above its long-term average, we have literally zero export growth over those years, and when the dollar is below its long-term average, we normally have double-digit growth of 12 to 15 percent, but these are longer term, not month to month or even quarter to quarter,” Vargo says.

The weakening dollar affects multinationals differently, says IHS Global Insight’s Gault. Multinationals tend to have plants and foreign earnings around the world, so they have a different calculus. “When the dollar declines, it makes it more profitable for them to produce in the United States rather than somewhere else, so it can influence where they decide to locate production, such as which facilities they decide to expand and which facilities they are cutting back,” he says.

Another benefit to multinationals is that a weaker dollar has a big effect on the dollar value of any profits they earn overseas. When the dollar is low, foreign profits translate into higher dollar earnings, which is not probably something that is relevant to small companies.

While the weak dollar helps exporters, it can also cause problems for importers, especially those who import raw materials for their manufacturing processes. For importers of copper or businesses that use a lot of oil, their dollar cost is going to go up in the next few months. Imports have declined this year, but that’s primarily because of weakening demand in the U.S. because of the recession.

Increasing exports for deficit countries such as the U.S. was one of the goals that the G-20 nations agreed during their summit meeting in Pittsburgh last month. Exporting countries like China and Germany agreed to stimulate domestic demand so they would not be so dependent on exports.

“We will need to work together as we manage the transition to a more balanced pattern of global growth,” the leaders said in a statement.

Officially, of course, the Obama administration continues to publicly support the idea of a strong dollar, but so far the government has not intervened in the foreign-currency markets to help support its value.