Paul Ehrlich, known for his controversial 'Population Bomb' predictions, predicted that humanity would collapse due to overpopulation, food production failure, and pollution in the 1970s and '90s, but instead saw food production and population growth booming. Despite these predictions, Ehrich was more than 6.75 billion people wrong. He also bet $1,000 that the prices of five metals, chromium, copper, nickel, tin and tungsten would increase due to scarcity in the 1980s but the price of the basket of metals declined by 43 percent. Despite this, he never acknowledged his errors and was never compelled to acknowledge his errors. Critics often call Ehrchel a "Malthusian," referring to late-18th/early-19th century English economist Thomas Malthus who predicted population would outgrow the food supply. Ehrcheche was not scientific research, but an alarmist polemic about overpopulation.