The Application of Quasi-Experimental
Methods in Education Research:
Applications Using Stata
Stephen L. DesJardins
Professor
Center for the Study of Higher and Postsecondary Education
School of Education and
Professor, Gerald R. Ford School of Public Policy
University of Michigan
AIRUM Conference Afternoon Workshop Session
November 6, 2013
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• Set up a logical folder structure to store do files (programs), data, & output files in
• Learn how Stata works & some basic commands
• Examine code to undertake IV analysis,
PSM modeling, and RD design methods
• Objectives are to provide an introduction to the Stata software, learn some different methodological applications, and discuss how these might be used in your research
2

• AIRUM 2013 (main folder located on C: drive)
– Articles (contains articles/chapters)
– Data Files (contains all data files)
– Do Files (contains all do files)
– Graphs (place to send all graphs created by code)
– Log Files (place to send output created by code)
– PowerPoints (contains all PowerPoints)
• Example:
– C:\AIRUM 2013\Data Files\IV_Data_File.dta
– /users/desjardins/datafiles/IV_Data_File.dta
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• IV_Data_File
– Contains SUR data from a state
– Outcome of interest:
• PSM_Data_File
– Contains SUR data from a state
– Outcome of interest:
• RD_Data_File
– Contains data from a large-scale college scholarship program
– Outcome of interest:
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• Called “do” files; contain Stata code/commands we “run” to produce results
• There is a do file associated with each set of analysis (IV, PSM, RD) we will conduct
• Are menu options for running commands in
Stata, but we will not use this method
– May be useful for some “on the fly” analysis, but it is NOT a good way to do most projects
– Reasons: reproducibility & transportability
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• Laying out a logical folder structure for each project is an important initial step in the analytic process
• If you use a similar structure all the time you will be able to efficiently come back to projects at later date & understand what was done
• Also very important to provide comments in your do files so you know what you did
6

• Command driven software
• Software resides in:
– C:\Program Files (x86)\Stata12
– Type: “adopath” on command line
• Role of “ado” files
– Examine ado & help files
• User written ado & help files
7

• Toolbar contains icons that allow you to Open &
Save files,
Print results, control Logs , & manipulate windows.
• Of particular interest: Opening the Do-File
Editor , the Data Editor and the Data Browser .
– Data Editor & Browser: spreadsheet view of data.
•
Do-File Editor allows you to construct a file of
Stata commands, save them, & execute all/parts
• The
Current Working Directory is where any files created in your Stata session will be saved
(by default). Don’t save stuff to here.
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• Review, Results, Command , & Variables windows.
•
Help : Search for any command/feature. Help
Browser , which opens in Viewer window, provides hyperlinks to help pages & to pages in the manuals
• May search for help using command line
• Role of “findit”
&
“ssc install”
– Locate commands in Stata Technical Bulletin & Stata
Journal; Demo loading the “psmatch2” command
– On command line type: “ssc describe psmatch2” then
“ssc install psmatch2” & then “help psmatch2”
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• Depending on your needs, there are a number of software options when purchasing Stata
• Single user/institutional/Grad Plan license
• Small vs. IC vs. SE versions
• Perpetual license; continually updated
• Stat Transfer software
• See the Stata website for more information: http://www.stata.com/order/educational-purchases/dl/
10

• Work on IV_Do_File first
•
• Then examine PSM file
• RD application last
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• These methods, and others, can be helpful in studying the effects of programs, process,
& practices where random assignment is not possible or feasible.
• They are regression-based so learning them is an extension of the OLS/logit training many have had
• The results can be displayed in a way so as to make them understandable to policy makers & administrators
12

• There are many resources available to learn
& extend these methods
– Higher education literature, Stata (and other) publications, blogs with code & solutions to programming/statistical problems
– Professional development workshops
• I hope you’ve found this exercise helpful & that you will be able to use these methods in your IR work
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