This help page documents the options that control the behaviour of the survey package.
All the options for the survey package have names beginning with "survey". Four of them control standard error estimation.
options("survey.replicates.mse") controls the default in
svrepdesign and as.svrepdesign for computing
variances. When options("survey.replicates.mse") is
TRUE, the default is to create replicate weight designs that
compute variances centered at the point estimate, rather than at the
mean of the replicates. The option can be overridden by specifying
the mse argument explicitly in svrepdesign and
as.svrepdesign. The default is FALSE.
When options("survey.ultimate.cluster") is TRUE,
standard error estimation is based on independence of PSUs at the
first stage of sampling, without using any information about
subsequent stages. When FALSE, finite population corrections
and variances are estimated recursively. See svyrecvar
for more information. This option makes no difference unless
first-stage finite population corrections are specified, in which
case setting the option to TRUE gives the wrong answer for a
multistage study. The only reason to use TRUE is for
compatibility with other software that gives the wrong answer.
Handling of strata with a single PSU that are not certainty PSUs is
controlled by options("survey.lonely.psu"). The default
setting is "fail", which gives an error. Use "remove"
to ignore that PSU for variance computation, "adjust" to
center the stratum at the population mean rather than the stratum
mean, and "average" to replace the variance contribution of
the stratum by the average variance contribution across strata. As
of version 3.4-2 as.svrepdesign also uses this option.
The variance formulas for domain estimation give well-defined,
positive results when a stratum contains only one PSU with
observations in the domain, but are not unbiased. If
options("survey.adjust.domain.lonely") is TRUE and
options("survey.lonely.psu") is "average" or
"adjust" the same adjustment for lonely PSUs will be used
within a domain. Note that this adjustment is not available for
replicate-weight designs, nor (currently) for raked,
post-stratified, or calibrated designs.
The fourth option is options("survey.want.obsolete"). This
controls the warnings about using the deprecated pre-2.9.0 survey
design objects.
The behaviour of replicate-weight designs for self-representing
strata is controlled by options("survey.drop.replicates").
When TRUE, various optimizations are used that take advantage
of the fact that these strata do not contribute to the variance.
The only reason ever to use FALSE is if there is a bug in
the code for these optimizations.
The fifth option controls the use of multiple processors with the
multicore package. This option should not affect the values
computed by any of the survey functions. If TRUE, all
functions that are able to use multiple processors will do so by
default. Using multiple processors may speed up calculations, but
need not, especially if the computer is short on memory. The best
strategy is probably to experiment with explicitly requesting
multicore=TRUE in functions that support it, to see if there
is an increase in speed before setting the global option.