Household Income in Irisdale, Springfield, Illinois (Neighborhood)

Household Income by Neighborhood in Springfield

There are 24 neighborhoods in Springfield. This section compares Irisdale to all of the neighborhoods in Springfield and to those entities that contain or substantially overlap with Irisdale.

Definitions

• Household Income: total income from all people in the household
• Median: in terms of income, it is the income for which 50% of households have a lower income, and 50% have a higher income
• Percentile: for example, the 80th percentile of household income is the income for which 80% of household have a lower income and 20% have a higher income
• Quintile: a quintile is 20% of a population, grouped by percentile; for example, the 2nd quintile is all members of a population between the 20th and 40th percentiles
• Gini Index: a statistical measure of how unevenly income is distributed in a population (ranging from 0% to 100%, the higher the number, the greater the inequality)

Unlike the other geographical entities detailed on this site, neighborhoods are not recognized by the U.S. Census Bureau. To overcome this we have computed reasonable estimates of the same statistics that are presented for other the entity types. Each statistic is computed as the weighted sum or average of the census tracts or block groups that overlap the neighborhood. A weighted sum is used for counts of people or households, and a weighted average is used for statistics that are themselves some form of average, such as median household income. Census block groups are preferred when the statistic in question is available on the block group level. The weight for a given tract (or block group) is computed as the population of the census tabulation blocks that occupy the intersection between the tract and the neighborhood as a fraction of the total population of the neighborhood.

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