Tents facing the open defecation field during Allahabad Kumbh Mela, February 2014 (User PraveenaSridhar, Flickr Commons) I spent eleven weeks conducting research and teaching in Asia this summer and, during a lull, revisited a classic travelogue I had originally read while on a similar trip twenty or so years before—American travel writer and novelist Paul Theroux’s Great Railway Bazaar: By Train Through Asia. Though now pushing forty, the book is still well worth reading, and some of its observations still ring true. One such instance relates to its discussion of the prevalence of open defecation in India. Theroux’s description is sufficiently scatological to not bear repeating here. Nevertheless, what caught his attention in one memorable passage was the sight of large numbers of people defecating on the railroad tracks as the train he was on pulled into a station in southern India—and, indeed, as the same train pulled out. The sight, according to Theroux, “seemed the perfect symbol for what a man in Delhi had called ‘The Turd World.’”

The Turd World is still with us, even if the term it plays off of has fallen into disuse. Occurrences of the kind Theroux described are still all too common in India and other emerging nations. Indeed, as experts from the United Nations and the World Health Organization pointed out in Geneva last May while announcing a major global initiative on health and sanitation, one billion people worldwide still practice open defecation. Of that number, 600 million reside in India. Open defecation creates a host of problems that exceed the merely aesthetic. The spread of numerous gastrointestinal and diarrheal diseases is associated with open defecation, whether through direct contact with fecal matter or via tainted food and water. As a result, high levels of morbidity and mortality directly attributable to open defecation plague societies in which the practice is commonplace. These nations also suffer reduced rates of economic growth and development as a consequence.

Another result—this one more positive—is that scholars have increasingly begun to focus on the role played by poor sanitation in both human and economic development in emerging societies. Whereas researchers once believed that impoverished people in less developed countries were sick because they were poor, further investigation has in many cases reversed the causative link between these two factors. Instead, scholars have found, people are often poor because they are sick. Illness makes individuals more susceptible to malnutrition, even in instances where adequate supplies of food are available. Sick and malnourished children are prone to physical and mental stunting. This makes them more likely to fail to attend school regularly or, when they do attend, to perform poorly. Sick and undereducated adults are often unable to hold onto jobs, which diminishes the likelihood that their children will fare any differently.  Open defecation, whether it occurs behind bushes, in groves of trees, in rivers or streams, or on the street (or, indeed, along railroad tracks), is a common trigger for this vicious cycle.

As problems related to open defecation gain greater attention, the importance of broader WaSH (water, sanitation, and hygiene) issues, such as global access to clean drinking water, have gained traction as well. This has increasingly led researchers to appreciate the close—but complex—relationship between these issues and the wider concern of emerging nations’ overall economic development trajectory. Many of the problems that complicate this relationship are multidimensional, having few easy, immediate, lasting, or ultimate solutions. But, for almost one out of seven people worldwide, one place to begin is by increasing access to even rudimentary latrines.

Both governments and NGOs operating in developing countries are well aware of the many problems arising from open defecation. For a variety of reasons, however, the problem has proven difficult to address, much less remedy. National ministries of finance preoccupy themselves with higher-profile priorities.  From a logistical standpoint, disseminating and maintaining cheap, functional, and durable latrines has not been easy. Even more problematic has been the issue of education. Poor rural areas are the principal sites of open defecation. Empowering the populations of these areas to understand the profound—and profoundly damaging—health and developmental consequences of open defecation has proven challenging. This phenomenon helps explain—though certainly not excuse—the fact that Indian Prime Minister Narendra Modi‘s campaign promise to privilege “toilets before temples” was quickly eclipsed in the media eye by news of his visit to the United States and his country’s recent probe of Mars. Probes over problems and distant planets over public health have become the de facto policy.

Eminent Oxford-based economist Sir Paul Collier published an important book in 2007 about the problems impeding economic development in the poorest countries in the world. Entitled The Bottom Billion, Collier’s book seizes on a number of common problems characteristic of such emerging nations. It ignores, however, the persistent problem of open defecation. Despite the fact that most open defecators do not reside in the world’s poorest countries but rather in highly populous developing countries such as India and Nigeria, open defecation is nonetheless a significant contributing factor to the ongoing poverty of many of the countries on which Collier focuses. Despite considerable progress made, the goal of halving the global population without access to safe drinking water and basic sanitation outlined in the UN’s Millennium Development Goals will expire in 2015 without being met. Fourteen years after passage of the MDG goals, seven years after Collier’s book, and forty years after Theroux’s, Collier’s “bottom billion” must be redefined. If the “bottoms” of a billion open defecators around the world remain unaddressed, they—and those affected by their behavior—will be the worse for it.