fastest growing major economy of the world in 2015, surpassing China. In 2018, as the U.S. Federal Reserve raised interest rates, fears of a yield curve inversion preceding a potential U.S. recession sent inflation higher in several emerging markets, including Argentina, where interest rates hit 40% and an International Monetary Fund bail out was issued. In 2019, Singapore supplanted the United States as the world's most competitive economy, with the U.S. dropping to third, behind Hong Kong. Global oil production in 2014 reached a historic peak, reaching 93 million barrels/day. In 2018, partially due to a shale boom, the United States overcame Russia and Saudi Arabia in becoming the world's largest crude oil producer, the first time since 1973. Around the year 2017 is a period seen by some economists as being the new peak of a "goldilocks economy". The International Monetary Fund's April 2019 World Economic Outlook stated, "After peaking at close to 4 percent in 2017, global [economic] growth remained strong, at 3.8 percent in the first half of 2018, but dropped to 3.2 percent in the second half of the year." In 2018, United States President Donald Trump announced he would put into place new tariffs on some Chinese products, starting the 'US-China Trade War', an economic conflict involving the world's two largest economies. Trump said the reasoning for the trade war is to punish China for 'unfair' trade practices, such as the appropriation of jobs and the theft of American intellectual property. China responded with tariffs of its own, and a cycle began, escalating the conflict to the situation faced today. As part of his 'America First' policy, Trump also announced new tariffs were being placed on countries around the world for various products such as steel and aluminium, which has drawn some economic retaliation. By the end of the decade, in North American and some Western European domestic economies, consumer-level purchasing habits had shifted significantly, a partial consequence of the Great Recession's impact on discretionary incomes and a shifting breadwinner model. The so-called "retail apocalypse" had commenced as consumers increasingly resorted to online shopping and e-commerce, accelerating the decline of brick-and-mortar retail and the continued decline of indoor shopping malls. The transitioning retail industry and popularity of online shopping facilitated economic phenomena such as bricks and clicks business models, pop-up and non-store retailing, drone delivery services, ghost restaurants, and a quickly maturing online food ordering