title: should R-squared and adj.R-squared be the same in a linear regression model with single predictor?
body: <p>I have run a model linear regression model with a single variable and the adj.R-squared is considerably lower than R-squared. As far as I know, adj. R-squared penalizes you for adding additional variables. </p>
  
  <p><strong>Where does the difference come from if there is one single predictor in the regression?</strong></p>