5: Correlation & Regression

Due Week 5 · Friday, September 25

Author

Prof. Jack Reilly

Published

Fall 2026

Instructions

For this assignment, you must turn in two documents:
1. Your answers (as a PDF), and
2. A plain-text .do file containing the Stata code you used to arrive at your answers.

For your assignment, please consider the following Protected_GDP.csv dataset. Import the dataset into Stata using the “File > Import > Text Data” command from the menu and answer the following questions. (Don’t forget to put the file import command into your .do file!)

Questions

  1. Find the mean, standard deviation, and range of each of the three variables: protected lands, GDP per capita, and total GDP. What is the average percentage of lands a country protects?

  2. Create a scatterplot where “protected lands” is on the Y axis and GDP per capita is on the X axis. Use Stata’s graphics editor to place a title and labels on the X and Y axis appropriately.

  3. Create a scatterplot where “protected lands” is on the Y axis and total GDP is on the X axis. Use Stata’s graphics editor to place a title and labels on the X and Y axis appropriately.

  4. Regress “protected lands” on GDP per capita. What is the slope of the line created when you regress protected lands on GDP per capita? What does this slope mean, substantively speaking? What is the intercept (or constant) term in the regression? What does it mean?

  5. Regress “protected lands” on total GDP. What is the slope of the line created when you regress protected lands on total GDP? What does this slope mean, substantively speaking? What is the intercept (or constant) term in the regression? What does it mean?

  6. If you knew nothing about a country’s GDP, what percentage of their lands would you guess to be protected?

  7. If you knew a country had a GDP per capita of $10,000, what percentage of their lands would you guess to be protected? What about $30,000? $50,000?

  8. Does raw GDP have the same relationship with protected lands as per capita GDP? How do you know?