Ecological regression is a statistical technique which runs regression on aggregates, often used in

political science Political science is the scientific study of politics. It is a social science dealing with systems of governance and power, and the analysis of political activities, political thought, political behavior, and associated constitutions and ...

and

history History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the History of writing#Inventions of writing, invention of writing systems is considered prehistory. "History" is an umbr ...

to estimate group voting behavior from

aggregate data Aggregate data is high-level data which is acquired by combining individual-level data. For instance, the output of an industry is an aggregate of the firms’ individual outputs within that industry. Aggregate data are applied in statistics, d ...

. For example, if counties have a known Democratic vote (in percentage) D, and a known percentage of Catholics, C, then running a

linear regression In statistics, linear regression is a linear approach for modelling the relationship between a scalar response and one or more explanatory variables (also known as dependent and independent variables). The case of one explanatory variable is ...

of dependent variable D against independent variable C will give D = a + bC. If the regression gives D = .22 + .45C for example, then the estimated Catholic vote (C = 1) is 67% Democratic and the non-Catholic vote (C = 0) is 22% Democratic. The technique has been often used in

litigation - A lawsuit is a proceeding by a party or parties against another in the civil court of law. The archaic term "suit in law" is found in only a small number of laws still in effect today. The term "lawsuit" is used in reference to a civil actio ...

brought under the

Voting Rights Act The Voting Rights Act of 1965 is a landmark piece of federal legislation in the United States that prohibits racial discrimination in voting. It was signed into law by President Lyndon B. Johnson during the height of the civil rights movement ...

of 1965 to see how blacks and whites voted.

See also

References

Further reading