Briefly explain whether each of the following statements concerning a cross-country regression of income per person on a measure of social infrastructure is true or false:

 

(a) “If the regression is estimated by ordinary least squares, it shows the effect of social infrastructure on output per person.”

 

(b) “If the regression is estimated by instrumental variables using variables that are not affected by social infrastructure as instruments, it shows the effect of social infrastructure on output per person.” (c) “If the regression is estimated by ordinary least squares and has a high R2, this means that there are no important influences on output per person that are omitted from the regression; thus in this case, the coefficient estimate from the regression is likely to be close to the true effect of social infrastructure on output per person.”