Incomes of Physicians an Economist Is Analyzing the Incomes of Physicians (General

question 131

Essay

Incomes of Physicians
An economist is analyzing the incomes of physicians (general practitioners,surgeons,and psychiatrists).He realizes that an important factor is the number of years of experience.However,he wants to know if there are differences among the three professional groups.He takes a random sample of 125 physicians and estimates the multiple regression model y = β₀ + β₁x₁ + β₂x₂ + β₃x₃ + ε,where y = annual income (in $1,000),x₁ = years of experience,x₂ = 1 if physician and 0 if not,and x₃ = 1 if surgeons and 0 if not.The computer output is shown below. THE REGRESSION EQUATION IS y = 71.65 + 2.07x₁ + 10.16x₂− 7.44x₃ S = 42.6 R−Sq = 30.9% ANALYSIS OF VARIANCE ​ ​
-{Incomes of Physicians Narrative} Is there enough evidence at the 1% significant level to conclude that general practitioners earn more on average than psychiatrists?

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Definitions:

Independent Variable

A variable that is manipulated or controlled in an experiment to observe its effect on a dependent variable.

Field Experiments

Research studies conducted in natural settings outside the laboratory to investigate the effect of manipulated variables in real-world situations.

Exact Replication

A type of replication of research using the same procedures for manipulating and measuring the variables that were used in the original research.

Procedures

A series of actions or operations conducted in a certain order or manner to achieve a result.