Background
Goodhart’s Law is named after Charles Goodhart, an economist born in 1936, who articulated this principle regarding economic policies and empirical measures. The law postulates that once a measure is targeted for use as an instrument of policy, it loses its reliability as a metric.
Historical Context
Charles Goodhart formalized his observations in the context of macroeconomic policy and econometrics during the late 20th century. His insights were particularly influential during a period when economic models and forecasts were becoming critical tools in policy formulation. Goodhart introduced this law in 1975 in response to policies that rely heavily on specific economic indicators.
Definitions and Concepts
Goodhart’s Law states: “Any observed statistical regularity will tend to collapse once pressure is placed upon it for control purposes.” This implies that once policymakers begin to target a specific empirical measure, the relationship between the measure and the wider economic reality changes, often making it less reliable.
Major Analytical Frameworks
Classical Economics
Goodhart’s Law reveals the limitations of classical economic theories that assume stable relationships between various economic indicators.
Neoclassical Economics
Within the neoclassical framework, Goodhart’s Law reinforces the need to consider how policies influence individual behavior and subsequent economic outcomes.
Keynesian Economics
Keynesian theories benefit from Goodhart’s Law as they emphasize the adaptive nature of economic agents to new policies, altering the expected impacts.
Marxian Economics
Goodhart’s observation underlines the dynamic interplay between policies and market responses, a truth also relevant to Marxian analysis focused on systemic and class changes in the economy.
Institutional Economics
Goodhart’s Law fits well with institutional economics that studies how institutions and policies affect economic behavior.
Behavioral Economics
Behavioral economics finds Goodhart’s Law crucial in understanding how individuals’ and firms’ decision-making processes adapt when policies modify the incentives and constraints they face.
Post-Keynesian Economics
Post-Keynesians regard Goodhart’s Law as vital, as it stresses the importance of historical context and the adaptive behaviors in economic modeling and policy design.
Austrian Economics
Austrian economists use Goodhart’s Law to criticize central planning and predict interventions will modify economic signals, leading to less predictable outcomes.
Development Economics
In development economics, the utility of Goodhart’s Law lies in highlighting that metrics should be used cautiously to avoid manipulating economic indicators instead of genuinely improving economic conditions.
Monetarism
Monetarists use Goodhart’s Law to argue for stable policy frameworks, as changing policies to target any empirical regularity could distort monetary metrics.
Comparative Analysis
Goodhart’s Law and the Lucas Critique share a common theme—the unpredictability introduced by policy interventions. While Lucas focuses on the forward-looking nature of expectations and how they alter with policies, Goodhart points out that changes in policy targeting specific metrics inherently make those metrics unstable.
Case Studies
Case studies often cited include the targeting of inflation rates by central banks. Early evidence suggested a reliable relationship between inflation and money supply, but once targeting began, this relationship became less stable. Another historical example is the use of GDP growth as an economic success indicator, which can lead to policies distorting genuine economic improvement efforts.
Suggested Books for Further Studies
- “A History of Economic Thought” by Lionel Robbins
- “Microeconomic Analysis” by Hal R. Varian
- “Advanced Macroeconomics” by David Romer
Related Terms with Definitions
- Lucas Critique: The theory that econometric models fail to predict the effects of new policies because they do not consider changes in people’s behavior in response to those policies.
- Economic Indicator: A statistical metric used to gauge future trends in a nation’s economy.
- Policy Regime: A stable set of policies governing economic activities in a country or region.
- Econometrics: The application of statistical methods to economic data to give empirical content to economic relationships.