Data Wrangling for Economists (EEA Annual Congress)

August 30, 2019

9:00 am - 4:00 pm

Instructors: François Michonneau, Miklós Koren, András Vereckei

Helpers: Douglas Lowe, László Tőkés

General Information

Data Carpentry develops and teaches workshops on the fundamental data skills needed to conduct research. Its target audience is researchers who have little to no prior computational experience, and its lessons are domain specific, building on learners' existing knowledge to enable them to quickly apply skills learned to their own research. Participants will be encouraged to help one another and to apply what they have learned to their own research problems.

For more information on what we teach and why, please see our paper "Good Enough Practices for Scientific Computing".

Who: The course is aimed at graduate students and other researchers. You don't need to have any previous knowledge of the tools that will be presented at the workshop.

Please fill in this anonymous quiz to help us gauge your Stata background and tailor the workshop to best fit your needs.

  1. Log in to Socrative.
  2. Enter the room code "STATAECONOMICS".
  3. Answer all four questions as best as you can.

Where: University of Manchester, University Place, Room 1.219. Get directions with OpenStreetMap or Google Maps.

When: August 30, 2019. Add to your Google Calendar.

Requirements: Participants must bring a laptop with a Mac, Linux, or Windows operating system (not a tablet, Chromebook, etc.) that they have administrative privileges on. They should have a few specific software packages installed (listed below).

Code of Conduct: Everyone who participates in Carpentries activities is required to conform to the Code of Conduct. This document also outlines how to report an incident if needed.

Contact: Please email korenm@ceu.edu for more information.

Surveys

Please be sure to complete these surveys before and after the workshop.

Pre-workshop Survey

Post-workshop Survey

Schedule

Before starting Pre-workshop survey
9:00-11:00 The Unix Shell (Episodes 1-3)
11:00-11:15 Break
11:15-12:00 Read and Explore Data
12:00-13:00 Data Formats and Data Quality
13:00-13:30 Lunch break
13:30-14:00Transform Data (reshape only)
14:00-15:00Save and Reuse Your Work in .do Files
15:00-15:15 Break
15:14-16:00Repeat Tasks with Loops
After the workshop Post-workshop survey

We will use this collaborative document for chatting, taking notes, and sharing URLs and bits of code.

Syllabus

The Unix Shell

Data Wrangling with Stata

Setup

To participate in a Data Carpentry workshop, you will need access to the software described below. In addition, you will need an up-to-date web browser.

We maintain a list of common issues that occur during installation as a reference for instructors that may be useful on the Configuration Problems and Solutions wiki page.

The Bash Shell

Bash is a commonly-used shell that gives you the power to do simple tasks more quickly.

Please download the zip file that contains the files we will use in the lesson.

Video Tutorial
  1. Download the Git for Windows installer.
  2. Run the installer and follow the steps below:
    1. Click on "Next" four times (two times if you've previously installed Git). You don't need to change anything in the Information, location, components, and start menu screens.
    2. Select "Use the nano editor by default" and click on "Next".
    3. Keep "Git from the command line and also from 3rd-party software" selected and click on "Next". If you forgot to do this programs that you need for the workshop will not work properly. If this happens rerun the installer and select the appropriate option.
    4. Click on "Next".
    5. Select "Use the native Windows Secure Channel library", and click "Next".
    6. Keep "Checkout Windows-style, commit Unix-style line endings" selected and click on "Next".
    7. Select "Use Windows' default console window" and click on "Next".
    8. Leave all three items selected, and click on "Next".
    9. Do not select the experimental option. Click "Install".
    10. Click on "Finish".
  3. If your "HOME" environment variable is not set (or you don't know what this is):
    1. Open command prompt (Open Start Menu then type cmd and press [Enter])
    2. Type the following line into the command prompt window exactly as shown:

      setx HOME "%USERPROFILE%"

    3. Press [Enter], you should see SUCCESS: Specified value was saved.
    4. Quit command prompt by typing exit then pressing [Enter]

This will provide you with both Git and Bash in the Git Bash program.

The default shell in all versions of macOS is Bash, so no need to install anything. You access Bash from the Terminal (found in /Applications/Utilities). See the Git installation video tutorial for an example on how to open the Terminal. You may want to keep Terminal in your dock for this workshop.

The default shell is usually Bash, but if your machine is set up differently you can run it by opening a terminal and typing bash. There is no need to install anything.

Text Editor

When you're writing code, it's nice to have a text editor that is optimized for writing code, with features like automatic color-coding of key words. The default text editor on macOS and Linux is usually set to Vim, which is not famous for being intuitive. If you accidentally find yourself stuck in it, hit the Esc key, followed by :+Q+! (colon, lower-case 'q', exclamation mark), then hitting Return to return to the shell.

nano is a basic editor and the default that instructors use in the workshop. It is installed along with Git.

Others editors that you can use are Notepad++ or Sublime Text. Be aware that you must add its installation directory to your system path. Please ask your instructor to help you do this.

nano is a basic editor and the default that instructors use in the workshop. See the Git installation video tutorial for an example on how to open nano. It should be pre-installed.

Others editors that you can use are BBEdit or Sublime Text.

nano is a basic editor and the default that instructors use in the workshop. It should be pre-installed.

Others editors that you can use are Gedit, Kate or Sublime Text.

Stata

This lesson uses the statistical package Stata™. It has been tested on Stata 15.1 MultiProcessor, but it should work on most recent versions.

If you do not have a Stata license, please let your instructor know so that they can request a short-term training license for free.

If you are newly installing Stata on your computer, follow these instructions.

  1. Go to https://download.stata.com/download/
  2. Log in using your username and password
  3. Click on your OS (64-bit Windows)
  4. Download and launch the installer.
  5. Once the installation is done, start Stata from the Start Menu. The first time you do this, you will have to activate your licence.
  6. Enter the serial number provided and press enter
  7. Enter the code and press enter
  8. Enter the authorization and press enter
  9. It should return “Good. The serial number, code, and authorization make sense. Shall we continue?” Type Y and press enter.
  10. When it asks for the first line, it should say “European Economic Association”
  11. When it asks for the second line, it should say “Manchester, UK”
  12. It will ask for confirmation. Type “Y” and press enter.
  1. Go to https://download.stata.com/download/
  2. Log in using your username and password
  3. Click on your OS (Mac)
  4. Download and launch the installer.
  5. Once the installation is done, start Stata from the Start Menu. The first time you do this, you will have to activate your licence.
  6. Enter the serial number provided and press enter
  7. Enter the code and press enter
  8. Enter the authorization and press enter
  9. It should return “Good. The serial number, code, and authorization make sense. Shall we continue?” Type Y and press enter.
  10. When it asks for the first line, it should say “European Economic Association”
  11. When it asks for the second line, it should say “Manchester, UK”
  12. It will ask for confirmation. Type “Y” and press enter.
  1. Go to https://download.stata.com/download/
  2. Log in using your username and password
  3. Click on your OS (64-bit Linux)
  4. Download Stata15Linux64.tar.gz.
  5. Open a terminal and navigate to the directory where your downloaded file is located (e.g. cd ~/Downloads/)
  6. Get superuser rights (sudo su)
  7. Create a new directory (e.g. mkdir stata_install)
  8. Move the downloaded file to this new directory (mv Stata15Linux64.tar.gz. stata_install/)
  9. Enter the directory (cd stata_install)
  10. Extract the installation files using tar xzf Stata15Linux64.tar.gz
  11. Create a directory for your stata installation (mkdir /usr/local/stata15)
  12. Navigate to the stata directory (cd /usr/local/stata15)
  13. Start the installation by executing the extracted install file (e.g. /home/username/Downloads/stata_install/install)
  14. Whenever the installer asks if you want to proceed type “y” and press enter
  15. Once the installation is done, type ./stinit to activate your licence
  16. Whenever it asks you if you want to continue, type “Y” and press enter
  17. Enter the serial number provided and press enter
  18. Enter the code and press enter
  19. Enter the authorization and press enter
  20. It should return “Good. The serial number, code, and authorization make sense. Shall we continue?” Type Y and press enter.
  21. When it asks for the first line, it should say “European Economic Association”
  22. When it asks for the second line, it should say “Manchester, UK”
  23. It will ask for confirmation. Type “Y” and press enter.

  24. Try to start stata by ./xstata. If it gives you the following error message (./stata: error while loading shared libraries: libpng12.so.0: cannot open shared object file: No such file or directory), continue with the steps below:

  25. Issue the following commands one by one in your terminal window: 
    apt-get install zlib1g-dev
      wget http://mirrors.kernel.org/ubuntu/pool/main/libp/libpng/libpng12-0_1.2.54-1ubuntu1_amd64.deb
      dpkg -i libpng12-0_1.2.54-1ubuntu1_amd64.deb