Recodes, dummy variables, and product terms can be generated temporarily within the program itself, so that the user will not have to create such variables before running a regression.

Ordinarily this program is invoked by the Web interface for the SDA programs, and the user does not have to deal with the keywords given in this document. Output from the program is in HTML, which can be viewed with a Web browser.

It is also possible to run the program directly by preparing a command file, which specifies the variables to be analyzed and the options to use. This document explains how to prepare such a file. The name of this batch command file is specified to the program after the ‘-b’ option flag.

In addition to the main results, one or more of the following optional statistics can be displayed. If the product of B times the mean (BPRODuct) is requested, univariate statistics are also included automatically. The ’OTHERstats’ keyword can be repeated.Keyword Possible Specification Default (if no keyword) _____________________________________________________________________COefficients= PROBIT Calculate logit regression coefficients and results STUdy= path of dataset directory Look for variables in current directory only SAvefile= filename to receive output Output sent to screen (overwrites existing file) (standard output) DEP= name of dependent variable REQUIRED INDep= names of independent vars REQUIRED (separated by spaces/commas) Weight= name of weight variable No weighting Filter= name(s) and codes of filter No filter variable(s) GVARCase= LOWER or UPPER No force to lower/upper case COLORcoding= Yes No color coding of coefficients or headings LAnguagefile= Name of file with non-English English labels on labels and messages output NDEcimals= number of decimals for results 3 decimal places (affects all major statistics) RUNtitle= Title or comments for run No title or comments TExt= Yes No text for variables

You can specify the desired number of decimal places in parentheses for univariate statistics and ’BPRODuct’ if the default, listed below, is not satisfactory. Note, however, that the number of decimals specified for ’BPRODuct’ will override the number specified for ’UNIvariate’.

There are some other options for the maximum likelihood estimation and for ASCII output of results. These options are not accessible from the standard SDA Web interface.Keyword Possible Specification Default (if no keyword) _____________________________________________________________________OTHERstats= TTests No T-tests EXPB No exp(B) for logit UNIvariate (ndec) No univariate statistics BPRODuct (ndec) No B*Mean statistics

Keyword Possible Specification Default (if no keyword) _____________________________________________________________________MAXIter= Maximum number of iterations 15 NOVerbose= Yes Report results of each iteration TOLerance= Tolerance for convergence .000001 ASCiifile= Name of file for ascii output Only HTML output

To change the default for univariate statistics or the product of B*Mean, put the desired number of decimals in parentheses after specifying the ’UNIvariate’ or ’BPRODuct’ keyword. If both are specified, the number of decimals for ’BPRODuct’ will override the specification for ’UNIvariate’.

# Basic example, specifying the dependent variable as a dummy variable study = /sa/testdata dep = spend(d:1-2) indep = age, educ gender savefile = mylogit.htm

----------------------------------- # Run a probit regression, with t-tests and univariate statistics. # Redefine some ranges; use weight and filter variables; # and request descriptive text for the variables. dep = spend(d:1-2) indep = age(18-30) educ gender coefficients = probit otherstats = ttests otherstats = univariate weight= wtvar filters= var21(1-3) var30(1) text = yes savefile = mylogit.htm

CSM, UC Berkeley

January 25, 2010