POLS/CSSS 503, University of Washington, Spring 2015

Due in lab: Friday, April 17, 2015 at 3:30 pm

Instructions

  1. Create a new R project for this homework named hw1 and load that project.
  2. Download the data file democracy.csv into the directory of that project.
  3. Do your analyses in an R markdown document.

  4. Submit a zipped file of the directory with your R project through Canvas. This should contain all the materials for another person to run your R Markdown fil This should contain:

    • The R project (.Rproj) file
    • The R Markdown document (.Rmd) of your analyses
    • An HTML document (.html) compiled from your R Markdown document.
    • Any data or other files neede to run the analyses in your R Markdown doceument.
  5. Turn in a paper copy of the document compiled from the analyses at lab.

  6. You can work together on this but you should each turn in your own assignments and write up your work separately. Include the names of your collaborators on your assignment.

Some other guidance

Data

The file democracy.csv contains data from Przeworski et. al, Demoracy and Deveolpment: Political Institutions and Well-Being in the Worlds, 1950-1990 1. The data have been slightly recoded, to make higher values indicate higher levels of political liberty and democracy.

Variable Description
COUNTRY numerical code for each country
CTYNAME name of each country
REGION name of region containing country
YEAR year of observation
GDPW GDP per capita in real international prices
EDT average years of education
ELF60 ethnolinguistic fractionalization
MOSLEM percentage of Muslims in country
CATH percentage of Catholics in country
OIL whether oil accounts for 50+% of exports
STRA count of recent regime transitions
NEWC whether county was created after 1945
BRITCOL whether country was a British colony
POLLIB degree of political liberty (1–7 scale, rising in political liberty)
CIVLIB degree of civil liberties (1–7 scale, rising in civil liberties)
REG presence of democracy (0=non-democracy, 1=democracy)

Problem 1

  1. Load the Democracy dataset into memory as a dataframe. Use the read.csv function, and the stringsAsFactors = FALSE option. Note that missing values are indicated by “.” in the data. Find the option in read.csv that controls the string used to indicate missing values.

  2. Report summary statistics (means and medians, at least) for all variables.

  3. Report a correlation matrix of all the variables in the dataset. You will need to find the function in R that calculates correlation. You will need to exclude the identifier columns. Watch out for missing values. Even though your input data containts missing values, your correlation matrix should not have missing values in any of its entries.

  4. Create a histogram for political liberties in which each unique value of the variable is in its own bin.

  5. Create a histogram for GDP per capita.

  6. Create a histogram for log GDP per capita. How is this histogram different than the one for GDP per capita when it was not logged.

  7. Create a scatterplot of political liberties against GDP per capita.

  8. When there is a lot of overlap in a scatter plot it is useful to “jitter” the points (randomly move them up and down). Make the previous plot but jitter the points to mitigate the problem of overplotting. (Only jitter the points vertically). You can use geom_jitter in ggplot2 for this.

  9. Create a scatterplot of political liberties against log GDP per capita. Jitter the points. How is the relationship different than when GDP per capita was not logged.

  10. Create a boxplot of GDP per capita for oil producing and non-oil producing nations.

  11. Calculate the mean GDP per capita in countries with at least 40 percent Catholics. How does it compare to mean GDP per captia for all countries?

  12. Calculate the average GDP per capita in countries with greater than 60% ethnolinguistic fractionalization, less than 60%, and missing ethnolinguistic fractionalization. Hint: you can calculate this with the dplyr verbs: mutate, group_by and summarise.

  13. What was the median of the average years of education in 1985 for all countries?

  14. Which country was (or countries were) closest to the median years of education in 1985 among all countries?

  15. What was the median of the average years of education in 1985 for democracies?

  16. Which democracy was (or democracies were) closest to the median years of education in 1985 among all democracies?

  17. What were the 25th and 75th percentiles of ethnolinguistic fractionalization for new and old countries?

Problem 2

  1. What is the dependent variable for your final project?
  2. Will you be writing this yourself, or with collaborators? Do you plan on submitting this work for another course?
  3. How do you plan on obtaining the data you need for analysis? What are your sources?
  4. Take the opportunity to do some preliminary exploratory analysis if you already have the data.

Derived from of Christopher Adolph, “Problem Set 1”, POLS/CSSS 503, University of Washington, Spring 2014. http://faculty.washington.edu/cadolph/503/503hw1.pdf; “Problem Set 2”, POLS/CSSS 503, University of Washington, Spring 2014 http://faculty.washington.edu/cadolph/503/503hw2.pdf. Used with permission.

  1. Przeworski, Adam, Michael E. Alvarez, Jose Antonio Cheibub, and Fernando Limongi. 2000. Democracy and Development: Political Institutions and Well-Being in the World, 1950-1990. Cambridge University Press.↩

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. R code is licensed under a BSD 2-clause license.