Econometrics Puzzler #2: Fitting a Regression with Fitted Values

Suppose I run a simple linear regression of an outcome variable on a predictor variable. If I save the fitted values from this regression and then run a second regression of the outcome variable on the fitted values, what will I get? For extra credit: how will the R-squared from the second regression compare to that from the first regression? Example: Height and Handspan Here’s a simple example: a regression of height, measured in inches, on handspan, measured in centimeters. 1 library(tidyverse