As the world becomes increasingly urbanized, the number of megacities is growing rapidly. Today there are 37 cities worldwide with populations of greater than 10 million, and 84 with populations…

Philip E. Karp, Peter Ellis, Barjor Mehta |

When Prime Minister Narendra Modi launched the Swachh Bharat Mission in 2014, it marked the beginning of the world’s largest ever sanitation drive. Now, a 2017 survey by the Quality Council of…

Guangzhe CHEN, Vinita Ranade |

Children in Koutoukalé, Niger Have you ever wondered how your life chances are affected by where you were born? Odds of being born at all are already miraculously small, but only one in ten of us…

Maximilian Leo Hirn, Aude-Sophie Rodella |

Many people were bitterly disappointed when four cases of wild polio were discovered in August 2016 in insecure areas of Borno State in the northeast of Nigeria. Nigeria had gone for almost two…

Mayowa Oluwatosin Alade, Benjamin Loevinsohn, Ayodeji Oluwole Odutolu |

A new study finds that child marriage could cost developing countries trillions of dollars by 2030, with the largest economic cost coming from its impact on fertility and population growth.…

Quentin Wodon, Suzanne Petroni |

May 17 is the International Day Against Homophobia, Transphobia and Biphobia, or IDAHOT.   Why should we care about IDAHOT? Because sexual orientation and gender identity, or SOGI, matters.   [[…

Ede Ijjasz-Vasquez, Clifton Cortez |

Globally 2.9 million people died from household air pollution in 2015, caused by cooking over foul, smoky fires from solid fuels such as wood, charcoal, coal, animal dung, and agricultural crop…

Ernesto Sanchez-Triana, Bjorn Klavdy Larsen |

Those who have tried toilet training a pet dog or cat know that it is a difficult proposition. How about toilet training a flock of 30 chickens? “Why would I want to?” Because in poor countries,…

Derek Headey |