Editor's note: David Bacon is a photojournalist who writes frequently on immigration and labor for the American Prospect, New America Media, and the Nation. His latest book, Communities Without Borders (Cornell University Press, 2006), presents a photographic view of transnational communities, including images and narratives from both sides of the border. Bacon is based in Northern California but has photographed immigrant communities throughout most of the United States, in parts of Central America, and most recently in Colombia.

What informs your photographs of immigrant communities and migrant workers?

I've been a documentary photographer for almost 20 years, and from the beginning I've been interested in documenting the effects of globalization on ordinary people -- people at the bottom. Because one of the main effects of globalization is migration, I've been very interested in immigrant workers.

I'm really interested in culture, and the way in which people bring their culture with them. I define culture pretty broadly, so it includes dances, food, language, and so on, but also includes the way communities are organized, the things that people do together. For instance, Mixtecs and other indigenous people from Oaxaca, Mexico, have a custom that they call the tequio, in which people work together on a common project to benefit the village they live in. People bring these traditions with them, of acting in an organized way, which I think is part of how migrant communities survive here in the United States.

It seems that we don't often hear migration discussed as a journey with myriad causes.

It's partly because the media cover migrants once they're here and don't give nearly as much attention to what happens in their communities of origin. There was some coverage, for instance, of the turmoil in Oaxaca, but it doesn't connect the dots -- it doesn't say that the same kinds of social conditions that are bringing people into the streets are also displacing them as communities and setting them into motion on the migrant trail to the United States.

We don't look deeply at the causes of migration, and when we do, we tend to think of them overwhelmingly in economic terms -- that people are coming to the United States because we have jobs here, and people don't have jobs in their communities of origin. Well, that's true. But people are more than just economic animals. One of the things that I've realized in doing this work is that the lack of human rights is itself a cause of migration. This is what we need more coverage of in the United States, because it would help us to understand how our government's economic and trade policies affect migration.

What are the ideas behind the photographs and narratives in your latest book?

The project was started to document the migration of indigenous people from southern Mexico and Guatemala to the United States. It's called Communities Without Borders because the migration of people is a process that involves whole communities, not just individuals. For instance, the people of a Mixtec-speaking town in Oaxaca begin to leave for the reasons we've been talking about, and if you are a member of that community, you can go through northern Mexico and come to the United States and find settlements of people who speak your language, who share your culture. It's like you belong to one large community that's located simultaneously in more than one place.