A researcher wants to study the effect of income on spending. She uses a dataset that contains information on spending by those who won a lottery last year. The dataset contains the following variables for each individual: S: (annual) spending (in thousands of dollars); Lott lottery winnings (in thousands of dollars); Inc (annual) income (in thousands of dollars, does not include Lott); Tot Inc: Lott + Inc. = The researcher estimates the following regressions (assuming homoskedasticity): Regressors Tot Inc Lott Inc Tot Inc log(Tot Inc) constant S (1) 0.728*** (0.0580) Observations S (2) 0.698*** 1.282 (4.232) 120 0.572 (0.0618) 0.202 (0.146) Dependent Variable: S (3) x1 x2 -2.096 x3 (4.874) 120 0.578 S (4) 0.693* 120 *** (0.209) 0.00226 (0.0129) log (S) (5) 0.0192*** (0.00260) 2.424 (7.777) (0.190) 120 120 R 0.572 0.315 The dependent variable in regressions (1)-(4) is S, and it is log(S) in regressions (5) and (6). Standard errors in parentheses; ** p