Water scarcity is growing even in parts of the world that used to be drought-free. Since  most countries waste vast quantities of water, charging for it would help. Our correspondent travelled to America’s northern border to report on illegal crossings from Canada (8:57). And the life of biological anthropologist Helen Fisher, who studied the science behind love (16:41).Listen to what matters most, from global politics and business to science and technology—Subscribe to Economist Podcasts+For more information about how to access Economist Podcasts+, please visit our FAQs page or watch our video explaining how to link your account. Hosted on Acast. See acast.com/privacy for more information.