Before revision: "The story [...] probably evokes for many readers a mental representation of a prototypical incident, perhaps an image of an exhausted bird, its feathers soaked in black oil, unable to escape,"p. 212 and subjects based their willingness-to-pay mostly on that mental image
After revision: ."The story [...] probably evokes for many readers a mental representation of a prototypical incident, perhaps an image of an exhausted bird, its feathers soaked in black oil, unable to escape,"p. 212 and subjects based their willingness-to-pay mostly on that mental image