The Colour of a Free Ride
通过让不同肤色的测试者假装没钱坐公交，观察司机是否免费让他们乘车，发现白人被允许免费乘车的比例是黑人的两倍，表明种族偏见在日常互动中普遍存在。
Abstract We use a natural field experiment to estimate the causal effect of race on discretionary favours in the marketplace. Test customers are randomly assigned to board public buses with no money to purchase a fare, leaving the bus driver to voluntarily decide whether to offer them a free ride. Based on 1,552 transactions, we uncover strong evidence of racial bias: bus drivers were twice as willing to let white testers ride free as black testers (72% vs. 36% of the time). Signals of wealth and patriotism improve minority testers’ outcomes. Our results show that white privilege extends to unregulated daily interactions.