为了衡量家庭被收入隔离的程度，提交人采取了三个步骤。首先，他们看看拥有最多人数的30名美国城市。其次，他们将家庭分类为下降，中间或高收入。“为了这个分析的目的，低收入家庭被定义为国家中位数和高收入家庭的三分之二，占全国中位年收入的两倍多。使用这些门槛，它需要一个年度家庭收入不到34,000美元，以标记为低收入，低收入和104,000美元或以上标记为上层收入。该中心进行了多次分析，使用不同的门槛来定义下层和高收入家庭。此处报告的基本发现无论使用哪些阈值，收入的分离都是一致的。“Third, they look at where households are living by Census tract: "The nation’s 73,000 census tracts are the best statistical proxy available from the Census Bureau to define neighborhoods. The typical census tract has about 4,200 residents. In a sparsely populated rural area, a tract might cover many square miles; in a densely populated urban area, it might cover just a city block or two. But these are outliers. As a general rule, a census tract conforms to what people typically think of as a neighborhood."
接下来，作者计算他们所谓的住宿收入分离指数，这来自“加入居住在大多数低收入的小家中的低收入家庭的份额以及居住在大多数高收入中的占有率的份额道路......（最大可能的RISI得分为200.在这种大都会地区，100％的低收入和100％的高收入家庭将位于一个人口普查的道路中，其中大多数家庭都在其收入相同括号。）“以下是1980年和2010年30个城市的RISI分数：
总体而言，国家指数从1980年到46年增加到2010年。该报告不寻求分析城市的差异，这可能受到一系列当地因素的影响。在区域一级，“人们发现西南部的地铁地区具有最高的平均RISI评分（57），其次是东北（48），中西部（44），西（38）和东南部（35）。分析还表明，大西南地铁地区收入的住宅隔离水平平均从1980年到2010年增加得比拥有该国其他地区的那些。但所有地区都有一些增加。“
在一个广泛的水平，收入分离的主要原因是美国的收入不平等上升：
"[T]here has been shrinkage over time in the share of households in the U.S. that have an annual income that falls within 67% to 200% of the national median, which are the boundaries used in this report to define middle-income households. In 1980, 54% of the nation’s households fell within this statistically defined middle; by 2010, just 48% did. The decline in the share of middle-income households is largely accounted for by an increase in the share of upper-income households. ... With fewer households now in the middle income group, it’s not surprising that there are now also more census tracts in which at least half of the households are either upper income or lower income. In 2010, 24% of all census tracts fell into one category or the other—with 18% in the majority lower-income category and 6% in the majority upper-income category. Back in 1980, 15% of all census tracts fell into one category or the other—with 12% majority lower and 3% majority upper. To be sure, even with these increases over time in the shares of tracts that have a high concentration of households at one end of the income scale or the other, the vast majority of tracts in the country—76%—do not fit this profile. Most of America’s neighborhoods are still mostly middle income or mixed income—just not as many as before."我没有强大的事先信念，关于收入的收入是多少，我没有理由认为1980年收入的住宅隔离程度是我们应该渴望的金色历史理想。但在美国经济上，在收入不平等上升，我们的经济和政治未来将取决于共同的互动，收入的住宅隔离程度上升确实给了我一种不安的感觉。
