1 / 10

Sample Design

STATISTICAL INSTITUTE OF JAMAICA. Sample Design. Establishments Surveys. Stuart Brown Research, Design & Evaluation January 2013. Sampling Frame. The Business Register (or Central Register of Economic Units - CREU) Does not include agricultural/government establishments

susan
Télécharger la présentation

Sample Design

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. STATISTICAL INSTITUTE OF JAMAICA Sample Design Establishments Surveys Stuart Brown Research, Design & Evaluation January 2013

  2. Sampling Frame • The Business Register (or Central Register of Economic Units - CREU) • Does not include agricultural/government establishments • Contains 7,459 establishments (as at Jan 24, 2013)

  3. Establishment Classifications • Employment size (total number of persons employed) • Small - less than 10 employees (<10) • Medium – between 10 and 49 employees (10-49) • Large - 50 or more employees (50+) • Industry • In accordance with Jamaica Industrial Classification (JIC) 2005

  4. Common Characteristics- Sample Design • Single-stage selection • Only establishments are selected randomly • Stratification by industry, size, geography • Large/Monopoly establishments – all selected • Medium establishments selected randomly • Some medium establishments may be selected with certainty (i.e. purpose selection) in special circumstances • Probability Proportional to Size (PPS) sampling within strata

  5. Selection Criteria • Large establishments are selected with certainty • All establishments within industries with six (6) or less establishments are taken • All establishments which are engaged in specific activities of interest are taken • PPS sampling method used to take sample from among medium establishments • Measure of size: employment size

  6. Sample Size Formula n = sample sizez = 95% confidence levelp = population proportionq = 1 - pe = margin of error e.g. If z=95%, p=40%, e=3% Then n = [(1.96)2 * 0.4 * (1-0.4)] / (0.03)2 = 1024

  7. Apportioning Groups within Sample • Calculate sample size • Identify groups from which all units will be selected, and separate from sample and frame • Determine proportions of groups in reduced frame • Apportion remaining sample according to proportions in reduced frame

  8. Sample Allocation Example:

  9. Response Rates • Ever declining • Usually much less than those for household surveys • Over-sampling done to compensate for expected non-response • Non-responding establishments not replaced • Out-of-business establishments replaced with establishments of similar characteristics • Weighting using sampling fractions and non-response rates

  10. END

More Related