Homework 5.1

Author
Affiliation

Alex Cardazzi

Old Dominion University

All materials can be found at alexcardazzi.github.io.

Question 1

Gun violence has been a particularly hot topic in the United States over the past few decades. According to the 2017 iteration of the Small Arms Survey, the United States is estimated to have over twice as many firearms per 100,000 people than the second highest country in the world. The introduction of “shall issue” policies, which mandate that authorities must issue concealed carry permits to applicants who meet specific criteria, has sparked considerable debate regarding their potential impact on crime rates. These policies, in contrast to “may issue” policies, remove discretion from authorities when issuing concealed carry permits. Proponents argue that such policies deter criminal activity by increasing the likelihood that potential victims are armed, thereby enhancing public safety. Critics, however, contend that more widespread gun carrying could escalate violence and lead to higher crime rates.

In this question, you will explore the effects these policies had on the violent crime rate, murder rate, and robbery rate. These data (data; documentation) contain data on 50 states, and DC, from 1977 to 1999.

  1. Read the data into a data frame called guns. Turn the law variable into a binary variable equal to one if the state has a “shall issue” policy for that year. (2 Points)

  2. Create a plot of the number of states with “shall issue” policies by year. Be sure to label the axes, etc. Set your \(Y\)-axis to range from 0 to 51, so as to capture a sense of how prevalent these polices are across all 50 states (plus D.C.). Be sure to label your axes, etc. (3 Points)

  3. Next, create a plot of the average violent crime rate by year. Be sure to label your axes, etc. (3 Points)

  4. Calculate the violent crime rate by year weighted by population. Since the violent crime rate is just that, a rate, it could make sense to increase the weight placed on rates impacting more people. In other words, to get a true picture of the violent crime rate faced by the average American, it would not make sense to consider the violent crime rates in California and Delaware equally. Create a plot displaying both the equally weighted and population weighted violent crime rates over time. Include a legend to differentiate between the two time series. Be sure to label your axes, etc. (6 Points)

  5. Estimate a simple model explaining log(violent) with only the indicator for whether the state has implemented a “shall issue” policy. Use heteroskedasticity robust standard errors. Display the coefficients (using summary() is fine) and interpret the coefficient. (4 Points)

  1. Add male, log(income), and log(density) into the model. Include state and year fixed effects as well. Display the coefficients (using summary() is fine). How does the “shall issue” coefficient change? Discuss if the signs of the other coefficients surprise you or if they conform to your expectations. What are the fixed effects doing? (6 Points)
  1. Just like how we can calculate weighted averages like in an earlier question, we can also estimate weighted regressions. Include weights = ~population into your feols() code and estimate the mode. Display the coefficients (using summary() is fine). How do the coefficients change, paying special attention to the “shall issue” coefficient? (4 Points)
  1. What is another variable not provided in the dataset that you wish you could incorporate into this model? How would you imagine the “shall issue” coefficient to change and why? Use an econometric argument to support your claim. (2 Points)

Question 2

Write a little bit about how your project is going (yes, you may vent a little…). What are you finding most time consuming? What has been most challenging? Be honest with yourself: is there anything you can be doing better? This one might be dangerous to ask, but are you enjoying your project? (20 Points)

Question 3

Fill out the course evaluation and include a screenshot as evidence. To include a screenshot, first place the image file in the same folder as your Homework 5.1 Template. Next, paste the file name, including the file’s extension (.png, .jpg, etc.), inside the the parentheses below. (5 Bonus Points) Note: evaluations are anonymous (and ultimately optional), so I am not looking to see what you wrote, just some confirmation that you have completed the survey. Also, evaluations are necessarily optional, which is why this question is for extra credit. (Another) Note: you may also leave any non-anonymous thoughts, opinions, suggestions, etc. about the course here as well if you’d like.

Screenshot Evidence of the Completed Survey