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How is the weighting of a sample used?
Weighting is one of the major components in survey sampling. For a given sample survey, to each unit of the selected sample is attached a weight that is used to obtain estimates of population parameters of interest (e.g., means or totals).
Why do we need to use weighted estimators?
Using weighted estimators leads to a better analysis of complex survey data. It should be noted that if the sampling design is self-weighted, using weighted or unweighted estimators gives the same results.
How to get an estimate of the population standard deviation?
An estimate of the population standard deviation can be obtained from estat sd after svy: mean. An estimate of the population standard deviation ( sigma) is given by
Why do we put some weight on Weights?
Because nonresponse reduces the effective size of the sample, it is necessary to adjust the weights (in fact, increasing them) to compensate for this loss. The adjustment of the design weights for nonresponse is the second step of the weighting process. The third step of weighting is to adjust the weights to some known population totals.
How are sample weights adjusted for attrition in NLSY79?
The child/young adult sample weights adjust for sample attrition of NLSY79 mothers and children (including the loss of the military and white oversamples) and for over-representation of black and Hispanic respondents.
How are sample weights calculated for the National Longitudinal Survey?
For the 1986-2000 survey years, two sample weight variables are available for each year: the originally released sample weight and a revised weight using the new algorithm. Weights are computed only for younger children who have been interviewed or young adults who have been fielded and interviewed in a given year.
What is the sample weight for a child?
A child sample weight (CSAMWTyyyy_REV or CSAMWTyyyy) GT “0” will indicate the number of children with either a Mother Supplement and/or Child Supplement. Please note that in 2000, four Young Adult respondents who were part of the pool of oversample cases that were not fielded were inadvertently interviewed.