make.truth {elec}

Make baseline truth for simulations

Description

For simulations. These methods, given an elec.data object, make a “truth”—i.e. a different vote count—that meets the same precinct and tot.votes structure, but has potentially different results and outcomes.

make.truth.opt.bad makes the “optimally worse truth”, where the error needed to flip the winner and runner-up is packed into as a few precincts as possible.

make.ok.truth makes the truth have the same outcome as the reported, but some errors here and there.

Warning: if bound is WPM this error is made by simply adding the max amount of error to the first loser's total (so that total votes may in this case exceed the total votes of the precinct)–this could potentially cause trouble. Be careful!

make bad truth as described in Stark's paper (assuming fixed precinct size)

Usage

make.truth.ex.bad(Z)

make.truth.opt.bad(Z, strata = "strata", bound = c("margin", "WPM"), t = 0)

make.truth.opt.bad.strat(Z, strata = "strata", t = 3, shuffle.strata = FALSE)

make.ok.truth(Z, num.off = 8, amount.off = 5)

Arguments

Z

The elec.data to build from.

strata

name of column holding strata, if any.

bound

What sort of maximum error can be held in a precinct.

t

an allowed backgound level of error for all precincts

shuffle.strata

Should the error be randomly put in the strata?

num.off

Number of precincts that should have small errors. Direction of errors split 50-50 positive and negative.

amount.off

Size of the small errors that should be imposed.

Value

Another elec.data matrix with the same candidates and total ballot counts as the passed frame, but with different candidate totals and by-precinct votes. Can be used to test the power or actual confidence of the various auditing procedures.

WARNING: make.ok.truth randomly adds votes and can thus sometimes exceed the allowed ballot count for a precinct by small amounts.

WARNING: If the desired bound is WPM, the error in make.opt.bad.truth is made by simply adding the maximum allowed amount of error in votes to the first loser's total (so that total votes may in this case exceed the total votes of the precinct)–this could potentially cause trouble. Be careful!

WARNING: make.truth.ex.bad and make.truth.opt.bad.strat only work in conjunction with the make.cartoon method.

Author(s)

Luke W. Miratrix

See Also

elec.data make.sample do.audit make.cartoon

Examples

## First make a fake election.
Z = make.sample(0.08, 150, per.winner=0.4, R=2.2)
Z

## Now make a fake truth, which has a lot of small errors:
Zb = make.ok.truth(Z, num.off=150, amount.off=5)
Zb

## Finally, make the hardest to detect (via SRS) ``wrong'' election:
Zw = make.truth.opt.bad( Z, t=4 )
Zw