Keep reading. You will find in Chapter 9 the section on "testing competitive theories," that I discuss critiques of Gilens and Page's analysis. I effectively dismiss Gilens's "responsiveness" to income groups analysis, and instead propose that a political class that is not "responsive" to any particular class is a more likely scenario.
Coming to this late, but later research has found considerable issues with Gilens' and Page's analysis. I'd take their conclusions with a grain of salt https://www.vox.com/2016/5/9/11502464/gilens-page-oligarchy-study
Keep reading. You will find in Chapter 9 the section on "testing competitive theories," that I discuss critiques of Gilens and Page's analysis. I effectively dismiss Gilens's "responsiveness" to income groups analysis, and instead propose that a political class that is not "responsive" to any particular class is a more likely scenario.