The world's richest man, Amazon CEO Jeff Bezos, saw his fortune increase to $112 billion last year, Oxfam said, pointing out that just one percent of his wealth was the equivalent to the entire health budget of Ethiopia, a country of 105 million people. The 3.8 billion people at the bottom of the scale meanwhile saw their wealth decline by 11 percent last year, Oxfam said, stressing that the growing gap between rich and poor was undermining the fight against poverty, damaging economies and fuelling public anger. "People across the globe are angry and frustrated," warned Oxfam executive director Winnie Byanyima in a statement. The numbers are stark: Between 1980 and 2016, the poorest half of humanity pocketed just 12 cents on each dollar of global income growth, compared with the 27 cents captured by the top one percent, the report found. Under-taxing the rich In the United States, new congresswoman Alexandria Ocasio-Cortez made headlines earlier this month by proposing to tax the ultra-rich up to 70 percent. The self-described Democratic Socialist's proposal came after President Donald Trump's sweeping tax reforms cut the top rate last year from 39.6 percent to 37 percent. And in Europe, the "yellow vest" movement that has been rocking France with anti-government protests since November is demanding that President Emmanuel Macron repeal controversial cuts to wealth taxes on high earners. "The super-rich and corporations are paying lower rates of tax than they have in decades," the Oxfam report said, pointing out that "the human costs -- children without teachers, clinics without medicines –- are huge". Oxfam found that asking the richest to pay just 0.5 percent extra tax on their wealth "could raise more money than it would cost to educate all 262 million children out of school and provide healthcare that would save the lives of 3.3 million people".