capture log close       //closes any open log file.
log using icpsrcda01-linear, replace text   //opens a log file that  
                                            //records both commands
                                            //and results.

//  program:    icpsrcda01-linear.do
//  task:       Review 1 - Linear Regression
//  project:    ICPSR CDA
//  author:     tait medina \ 2009jun20

// #1
// program setup

version 10              //this command is for version control, 
                        //ensuring that results can be replicated.
clear all               //this command removes data, value labels, matrices, 
                        //scalars, saved results, etc from memory.
set linesize 80         //specifies screen size width.
   


// #2
// Load the data 

    use icpsr_scireview3, clear


// #3
// Examine data and select variables

    codebook, compact
    
    keep totpub faculty enrol phd


// #4
// Drop cases with missing data and verify

    misschk, gen(m)
    tab mnumber
    keep if mnumber==0

    tab1 faculty enrol, miss        //use tab to look at categorical vars.
    sum phd                         //use sum to look at continuous variables.
    

// #5
// Regression

    regress totpub faculty enrol phd


// #6
// Standardized coefficients

    listcoef, help


// #7
// Interpretations


// #8
// Close log file and exit do file

    log close                       //closes log file.
    exit                            //exit from the do-file.