surveyoptions             package:survey             R Documentation

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_D_e_s_c_r_i_p_t_i_o_n:

     This help page documents the options that control the behaviour of
     the survey package.

_D_e_t_a_i_l_s:

     All the options for the survey package have names beginning with
     "survey".  Three of them control standard error estimation.

     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.

