Urban decline refers to a process that includes population loss and the concentration in cities of major social, economic, and environmental problems, such as high levels of unemployment and poverty and the deterioration of housing and public infrastructure. Sometimes used interchangeably with the terms urban decay and urban distress, urban decline is frequently measured by changes in population (particularly in relation to middle- and upper‐income residents), unemployment, and poverty rates; changes in median household income; and changes in property values, housing tenure, and vacancy rates.