Sociology 229A: Event History Analysis

Short Assignment #3: EHA Models

Due: Start of class (2:00) April 29

This assignment requires a dataset on the course website entitled “Assignment 3 Environment.dta” and an accompanying do-file.

Regarding the data: The unit of analysis is the nation-state. The outcome of interest is first enactment of major pro-environmental legislation.

1. Download the dataset in STATA
2. Create your own “do” file that opens the data
3. My syntax makes a hazard plot and runs some hazard models. See if you can get that same syntax to run on your computer without error. Make your own do-file, don’t just use mine!
4. Interpret the output of a basic exponential (constant-rate) hazard model:
1. What is the effect of a 1-point increase in degradation on the hazard rate of enactment?
2. What is the effect of a 1-point increase in democracy?
3. What is the (approximate) range of the democracy variable in the data? (It is OK to round off the difference in democracy to an integer.) What is the difference in hazard rate between the least-democratic and most-democratic cases?
4. Look at the Cox model results. Note two or three of the big differences in the output and/orfindings.
5. What is the effect of a 1-point increase in democracy, based on the Cox model?
5. Based on the limited information you have so far, which model do you think is most appropriate: the Cox model or the constant-rate model? Why?

Turn in the following:

1. The output from your Cox model
2. Answers to the questions