suf(1)

NAME

suf - Identify sufficient conditions

SYNOPSIS

suf [OPTIONS]

DESCRIPTION

Test for sufficient conditions.

OPTIONS

  Specification of Causal and Outcome Conditions

-o, --outcome=COLUMN
    Outcome column (default is last column)

-i, --include=COLUMNS
    Include only these causal conditions (default is all)

-I, --exclude=COLUMNS
    Don't include these as causal conditions

For these three options, COLUMNS may be specified by column position or name. Separate multiple COLUMNS with commas.

  Analysis Parameters

-s, --simplify=PARAMETER
    How aggressively should the routine reduce the truth table? Accepted parameters are:

        0 - Reduce truth table to primitive expressions
        1 - Reduce truth table to prime implicants (default)
        2 - Reduce prime implicants (equivalent to fs/QCA's
              "complex solution")
        3 - Reduce prime implicants using remainders as simplifying
              assumptions (equivalent to fs/QCA's "parsimonious
              solution")

-f, --freq=VALUE
    Frequency threshold (default is 1)

-c, --consist=VALUE
    Consistency threshold (default is 0.9)

-p, --prop=VALUE
    Proportion threshold (default is 1.0)

-e, --readtt=FILE
    Read in truth table from external file; don't convert dataset to truth table

-y, --input=FILE
    If absent, or when FILE is -, read standard input

VALUE is a number ranging between 0.0 and 1.0. For -e, FILE is a plain text representation of a truth table, such as is produced by suf or gtt. For -y, FILE is a dataset.

  Diagnostics

-d, --dataset
    Print dataset

-D, --Dataset
    Print dataset and exit

-t, --truthtable
    Print truth table

-T, --Truthtable
    Print truth table and exit

  Other Options

-h, --help
    Display help and exit

-v, --version
    Output version information and exit

Mandatory arguments to long options are also mandatory for short options.

Differences between suf and fs/QCA

suf uses the same "truth table algorithm" as fs/QCA and which is described in Redesigning Social Inquiry (Ragin 2008). However, there are a handful of important differences between suf and fs/QCA:

•   suf supports "Impossible" conditions, combinations of causal conditions that cannot occur. If a truth table row is marked as "Impossible," that row will not be included as a remainder when constructing the parsimonious solution.

•   suf also supports fuzzy-set contradictions, as described in "Contradictions in fsQCA" (Rubinson 2011). A contradiction is a truth table row in which the ratio of consistent:inconsistent observations falls below a given threshold (specified by --prop).

•   suf does not provide an equivalent to fs/QCA's "intermediate" solution. As described in "Between Complexity and Parsimony" (Ragin and Sonnett 2004), it is often the case that a range of intermediate solutions can be constructed for a given analysis. Rubinson's position is that it would therefore be misleading for suf to produce a single intermediate solution.

•   suf eliminates fs/QCA's pop-up prime implicant chart. In certain instances (known as "codominance" in Quine-McCluskey parlance), the QCA truth table reduction algorithm can produce more than one solution covering a given observation (or set of observations). When encountering such a situation, fs/QCA pops up a prime implicant chart for the user to resolve. This tends to confuse even experienced QCA practitioners. Instead, suf simply returns all solutions. The codominant solutions are easily identified because they will share the same set of observations and their unique coverage will be 0.0. It is then up to the researcher to determine which solutions to retain. A researcher might choose to retain only one of the codominant solutions, dropping the others as redundant. Alternatively, a researcher might choose to retain multiple solutions and argue that these observations are "overdetermined"--that they possess multiple combinations of causal conditions, any one of which are sufficient to produce the outcome.

SEE ALSO

bq(1), concov(1), consist(1), gtt(1), nec(1)

AUTHORS
Claude Rubinson <cjr@grundrisse.org>.