Please provide answers for only question 3 and 4. Question 2 is attached for reference, it does not need to be solved. Use R programming language and the data provided above to answer question 3 and 4. Thank you.

Leader Assassination as a Natural Experiment One longstanding debate in the study of international relations concerns the question of whether individual political leaders can make a difference. Some argue that leaders with different ideologies and personalities can significantly affect the course of a nation. Others argue that political leaders are severely constrained by historical and institutional forces. Did individuals like Hitler, Mao, Roosevelt, and Churchill make a big difference? The difficulty of empirically testing these arguments stems from the fact that changes in leadership are not generally random. In this exercise, we consider a natural experiment in which the success or failure of assassination attempts may be essentially random, at least with respect to the outcomes in which we are interested. This exercise is based on: Jones, Benjamin F, and Benjamin A Olken. 2009. "Hit or Miss? The Effect of Assassinations on Institutions and War." American Economic Journal: Macroeconomics 1(2): 55-87. Each observation of the CSV dataset leaders.csv contains information about an assassination attempt. The variables are: The polity variables represent "Polity scores" from the Polity Project. The Polity Project assigns an annual Polity score to all countries in the world from 1800 to the present as a measure of each country's political institutions. The Polity score is a 21-point scale ranging from -10 (hereditary monarchy) to 10 (consolidated Many researchers collapse the Polity scores to create binary autocracy/democracy indicators, because it is not clear that the Polity scores can or should be interpreted as measuring linear variation from autocracy to democracy. We will do that, too. First, create a new binary pre-assassination democracy variable in the dataset that is equal to 1 if politybefore is greater than 0, and equal to 0 otherwise (hint: the ifelse command will be helpful here). Next, create a new binary post-assassination democracy variable in the dataset that is equal to 1 if polityafter is greater than 0 , and equal to 0 otherwise. What proportion of countries in which assassination attempts occurred were democracies in the three years prior to the attempt, as measured by your new democracy variable? What proportion of countries in which assassination attempts occurred were democracies in the three years after the attempt, as measured by your new democracy variable? In order to investigate whether successful assassinations affect countries' political institutions and likelihood of being involved in a war, we need to assess whether there are any confounders that might affect both assassination success and changes in post-assassination outcomes. Identify three variables in the dataset that might plausibly be confounders as described above. For each variable, explain why we might think that the variable might affect both assassination success and changes in post-assassination outcomes. Answer 3 Insert written answer here. Question 4 We can explore the potential for confounding using our data. Using your newly created pre-assassination democracy variable, what proportion of countries were democracies prior to unsuccessful assassination attempts? What proportion of countries were democracies prior to successful assassination attempts? (Hint: you may want to use either the subset() command or brackets [] to select subsets of observations.) What does this tell you about whether pre-assassination political institutions are likely to be a confounder in an analysis of the effect of assassination success on post-assassination outcomes? Likewise, what was the mean leader age prior to unsuccessful assassination attempts? What was the mean leader age prior to successful assassination attempts? What does this tell you about whether leader age is likely to be a confounder in an analysis of the effect of assassination success on post-assassination outcomes? Answer 4 \#\# insert code here Insert written answer here