Search for dissertations about: "Risto Lehtonen"

Found 2 swedish dissertations containing the words Risto Lehtonen.

  2. 1. Calibration Adjustment for Nonresponse in Sample Surveys

    Author : Bernardo João Rota; Thomas Laitila; Sune Karlsson; Risto Lehtonen; Örebro universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Auxiliary variables; Calibration; Nonresponse; principal com-ponents; regression estimator; response probability; survey sampling; two-step estimator; variance estimator; weighting; Statistics; Statistik;

    Abstract : In this thesis, we discuss calibration estimation in the presence of nonresponse with a focus on the linear calibration estimator and the propensity calibration estimator, along with the use of different levels of auxiliary information, that is, sample and population levels. This is a fourpapers- based thesis, two of which discuss estimation in two steps. READ MORE

  4. 2. Cost efficency of nonresponse rate reduction efforts : an evaluation approach

    Author : Sara Westling; Bengt Swensson; Risto Lehtonen; Örebro universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; nonresponse bias; follow-ups; response distribution; resource allocation; cost efficiency; evaluation; nonresponse error; Monte Carlo simulations; Statistics; Statistik; Statistics; Statistik;

    Abstract : Nonresponse, the failure to obtain complete measurement on all sample elements, is an increasing problem in sample surveys. Efforts to reduce the nonresponse rate are expensive and their effect may not be as desired. READ MORE