Assignment 6: R APIs and Databases

1 Accept Assignment on Github Classroom

1. Accept Assignment 6 on Github Classroom.

2. Clone this assignment to your computer.

3. Intitialize your own renv environment.

2 Set up “secrets.r” file

• Copy the “secrets-template.r” file to a new “secrets.r” file

This will be where you will store your personal API keys and passwords.

I have already added “secrets.r” to the “.gitignore”, so it should not be tracked or pushed to Github.

3 FRED API

3.1 Pull FRED Series

• Get an API Key from FRED. Save it in your “secrets.r” file.

You will need to use the fredr package for this section.

• Pull the following data series
  • Real GDP: “GDPC1”
  • Rhode Island Unemployment Rate: “RIUR”
  • US-Euro Spot Exchange Rate: “DEXUSEU”
  • One more series of your choice, look around FRED’s website
• For each series, calculate the following:
  • Mean
  • Median
  • 25th Percentile
  • 75th Percentile
• Now report the same summary statistics, but only with data since 2020

3.2 Vintage FRED

• Pull Real GDP using a vintage date

  • There is a vintage_dates argument in the fredr() function.

• Calculate the difference between the current and the vintage data series (if there is no difference, try another vintage date)

• Print out the date with the maximum difference

4 tidycensus API

• Request a Census API key: https://api.census.gov/data/key_signup.html

  • Save it to your “secrets.r” file

• Install the sf package

  • Check their documentation if you have trouble

• Install the tidycensus package

• Pull median household income: “B19013_001” from the ACS¹

  • But choose a different state than Rhode Island

• Create a map with the data and ggplot2

  • Follow the example in the slides

¹ Same as the example in the slides.

(Optional) Mapview

If you want to try making one of those interactive maps, install the package mapview and give it a go.

5 Connect to WRDS Database

• First, get access to WRDS through Brown Univesrity Library

Warning

This can take 1-2 days to get access.

• Once you have an account, make sure you can log into WRDS online: https://wrds-www.wharton.upenn.edu

• Then add your account username and password to the “secrets.r” file.²

• Then open up the “get-wrds-data.r” script

  • The connection to the WRDS database should already work
  • Run the example in the code (same as what we saw in class)
  • Find another database to connect to and pull a subset of the data
    • I’d suggest looking around on the WRDS website to see what data is available

² Sometimes you have to approve the connection through the Duo app on your phone.

6 Submit

• Take a renv::snapshot() to update your renv.lock file
• Commit your code and push to Github!