Maximum Likelihood Estimator

An overview of Maximum Likelihood Estimator (MLE), a method used to estimate unknown parameters of a distribution by maximizing the likelihood function of the sample.

Background

The Maximum Likelihood Estimator (MLE) is a fundamental concept in statistics and econometrics, serving as a powerful tool to estimate the unknown parameters of a statistical model. MLE leverages the likelihood function, which measures how well a set of parameters explains the observed data. By maximizing this function, one can obtain estimates that are most plausible given the data.

Historical Context

The concept of Maximum Likelihood Estimation was developed by the British statistician Sir Ronald A. Fisher in the early 20th century, particularly during the 1920s. Fisher’s contributions significantly advanced statistical theory and methods, impacting numerous fields such as economics, genetics, and psychology. MLE has since become a cornerstone in statistical inference and is widely used in various applied econometric analyses.

Definitions and Concepts

  • Maximum Likelihood Estimator (MLE): An estimator of unknown parameters of a distribution obtained by maximizing the likelihood function of the sample.

  • Likelihood function: A function of the parameter(s) of a statistical model given specific sampled data, representing the probability (or likelihood) of the observed data under those parameter(s).

  • Parameter(s): The unknown values in a statistical model that are estimated using observed data via methodologies such as MLE.

Major Analytical Frameworks

Classical Economics

Classical economics primarily focuses on macroeconomic issues, such as economic growth and market equilibrium. While MLE is not typically central to classical theory, its methods can be applied in historical economic data analysis for estimating structural parameters of models.

Neoclassical Economics

Neoclassical economics heavily employs mathematical modeling, and MLE is valuable in estimating the parameters of various economic models related to supply, demand, and market behavior.

Keynesian Economics

In Keynesian analysis, MLE can be used to estimate parameters of models concerning aggregate demand, investment functions, and wage and price dynamics. These estimates help better understand macroeconomic phenomena and policy impact.

Marxian Economics

In Marxian economics, MLE may support the empirical investigation into the labor theory of value and the distribution of income and wealth.

Institutional Economics

Institutional economists might use MLE to estimate parameters in models that account for the role of institutions and social norms in economic outcomes.

Behavioral Economics

MLE is valuable in behavioral economics for estimating parameters in models that integrate psychological insights and decision-making anomalies into traditional economic models.

Post-Keynesian Economics

Post-Keynesian economists could use MLE to estimate non-linear and dynamic models that differ from neoclassical approaches, enhancing the understanding of uncertainty and human psychology in macroeconomic outcomes.

Austrian Economics

Although Austrian economists primarily emphasize qualitative methods, MLE can occasionally support empirical work investigating the consequences of monetary and fiscal policies they critique.

Development Economics

MLE is crucial in development economics to estimate models that analyze issues like poverty, inequality, and the impacts of development aid and policies.

Monetarism

Monetarists might use MLE for estimating models related to the quantity theory of money and understanding the empirical relationship between money supply and inflation.

Comparative Analysis

MLE serves as a versatile tool across different economic schools of thought for empirical validation and parameter estimation. Its application promotes the rigor of econometric analysis by providing efficient, consistent, and asymptotically normal estimators, compared to other methods such as Method of Moments or Least Squares.

Case Studies

Case studies in econometrics often demonstrate the application of MLE, such as estimating parameters of demand functions, analyzing time-series data for macroeconomic forecasting, or quantifying the effects of policy interventions.

Suggested Books for Further Studies

  1. “Econometrics” by Fumio Hayashi
  2. “Introduction to Econometrics” by James H. Stock and Mark W. Watson
  3. “Likelihood-Based Inference in Econometrics” by Donald W.K. Andrews
  • Estimator: A rule or procedure for estimating an unknown parameter based on observed data.
  • Method of Moments: An alternative estimation method where parameters are estimated by equating sample moments with theoretical moments.
  • Ordinary Least Squares (OLS): A common method to estimate the parameters of a linear regression model by minimizing the sum of squared residuals.
  • Bayesian Estimator: An estimator derived by incorporating prior distributions of the parameters and updating beliefs based on the observed data.

Use this entry as a fundamental resource to understand the role and importance of Maximum Likelihood Estimator (MLE) in the field of economics.

Wednesday, July 31, 2024