A comprehensive analysis of long-term trends in SPM poverty in the United States, 1967 to 2024

• In Event: New Research on Long-term Trends in Income Poverty in the United States

Abstract

A comprehensive re-analysis of long-term trends in historical SPM poverty in the United States, 1967 to 2024 Poverty is a key indicator assessing trends, group differences, and regional differences in the experience of poverty. This paper re-analyzes long-term trends in SPM poverty taking advantage of various definitions of poverty thresholds and the resources concept in comparison to those thresholds. The paper provides a comprehensive assessment of those trends across different types of thresholds, with and without various taxes and transfers included in the resource concept, by different income-to-needs thresholds, and across a wide array of demographic subpopulations. The SPM utilizes an income-based concept of (essentially) family resources, and those resources are compared against a definition of needs that is meant to correspond between the resources and thresholds concepts.Using the CPS ASEC merged with Columbia’s historical SPM data (now available for wide download for the research community via IPUMS), the paper provides long term trends in poverty by the following characteristics:

Four definitions of poverty thresholds: historical quasi-relative SPM thresholds; anchored absolute poverty thresholds anchored in the year of the starting year of the series (1967); anchored absolute poverty thresholds anchored in a year 55 years later, in 2022; fully relative poverty thresholds that are more common in international poverty literatures; these thresholds are adjusted with and without accounting for geographic differences across areas to the threshold concept

Different definitions of resources, including with and without resources from various tax and transfers, and with and without resource adjustments like subtraction of various non-discretionary expenses, etc.

Across different resource-to needs levels like twice the above poverty lines and three times the above poverty lines;

Across major demographic subgroups of: gender, race/ethnicity, age, family structure, and geographic region.

Though few argue that the SPM should be the only measure of poverty that is tracked over time, and not all scholars agree that it should be the principal or primary measure; the paper argues that it nevertheless reveals important insights into all of these trends and differences across groups and places over time.

Author

• Christopher Wimer, Columbia University
  Presenting Author