BOSTON COLLEGE
Department of Economics

EC 228 Econometrics, Prof. Baum, Mr. Barbato, Spring 2003

Problem Set 3

Due at classtime, 19 February 2002

Problem sets will not be accepted after their due dates. Please make sure your name is legible on each page of your answers.

For some these problems, you must use Stata, but will not make use of the RAW files listed in the text, as all of these data are available in Stata format over the Internet. Please consult the "Wooldridge datasets: descriptions and access commands" link on the course home page. All you need to do is copy the "use http://fmwww..." line from each dataset to be used into Stata's command window. The name of each dataset is that given in the text, without the .RAW extension; e.g. LAWSCH85.RAW is referred to as just LAWSCH85 (with no period nor extension). For example,

. use http://fmwww.bc.edu/ec-p/data/wooldridge/lawsch85

For each of the empirical problems, hand in a printout from Stata, annotated with your comments. The "log" icon in the Stata toolbar may be used to create a file containing both your commands and Stata's response. It may be easier to work with a text-format log; the command 'log using ps3.log' will create a text log. Use the 'Viewer' within Stata to examine and print the log.

All Stata problems in this problem set may be performed with Small Stata (which has a limit of 1,000 observations) as well as Intercooled Stata (available in the SLSC). Either Version 7 or Version 8 of Stata may be used.

You are encouraged to review the "Worked examples", linked to our course home page, at 

http://fmwww.bc.edu/gstat/examples/wooldridge/wooldridge.html
which illustrate many Stata commands' use in the context of the textbook examples.