[R] New package: BOOLEAN

[Bear F. Braumoeller]

I am writing to announce the availability of a new package on CRAN:  
"boolean," which permits users to run Boolean logit and probit analyses.


BACKGROUND
The impact of independent probabilistic causal processes is often  
thought to cumulate in a manner consistent with Boolean logic --  
specifically, a logic in which the atomic elements are connected by  
"and" or "or."  For example, diet or heredity can lead to heart  
failure, apathy or indifference can lead to nonvoting, plant survival  
depends on light and water and proper soil, and so on.  This form of  
cumulation has been referred to as "causal complexity" or "multiple  
causal paths" to a given (non-)outcome (see e.g. Ragin 1987).

The boolean() command is designed for use in such situations.  It  
models the probabilities of the antecedent processes ("paths") as logit  
and probit curves, constructs a likelihood function from the logic of  
their interaction, and maximizes to obtain parameter estimates.  Any  
number of causal paths can be modeled, in any combination -- A and B  
and C cause Y, A and (B or (C and D)) cause Y, etc.  For more details  
and the derivation of the procedure see <a  
href="http://www.people.fas.harvard.edu/~bfbraum/">Braumoeller  
(2003)</a>.


PACKAGE
In addition to performing Boolean logit and probit analyses, the  
boolean package contains functions to assist the user in a variety of  
ways:

    * boolprep() simplifies input for the boolean command

    * boolfirst() graphs first differences after estimation

    * boolprof() produces profile likelihoods for diagnostics

In addition, the plot() command produces an array of graphs of first  
differences or profile likelihoods for all of the relevant coefficients  
in the model.

For more information please visit <a  
href="http://www.people.fas.harvard.edu/~bfbraum/">http:// 
www.people.fas.harvard.edu/~bfbraum/</a>


REFERENCES
Braumoeller, Bear F. (2003) "Causal Complexity and the Study of  
Politics."  Political Analysis 11(3): 209-233.
Ragin, Charles C. (1987) The Comparative Method: Moving Beyond  
Qualitative and Quantitative Strategies.  Berkeley: University of  
California Press.


<A HREF="mailto:bbraumoeller at wcfia.harvard.edu">Bear F. Braumoeller</A>
Assistant Professor
Department of Government
Harvard University