While comparing economic data, a group of sociologists concluded that, among all people at a certain income level, individuals in rural areas have greater purchasing power than those living in urban or suburban regions. The group factored in several data points, including the population density within a certain radius of city centers, the number of people per household, and the percentage of those households that included two working parents. Ultimately, however, the main premise was that the money spent by urban and suburban dwellers on their fundamental need for food and shelter could be spent by rural households on discretionary items. From the passage above, it can be inferred that