A generalized estimating equations approach for analysis of the impact of new technology on a trawl fishery

Janet Bishop, David Die, You Gan Wang

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


The article describes a generalized estimating equations approach that was used to investigate the impact of technology on vessel performance in a trawl fishery during 1988-96, while accounting for spatial and temporal correlations in the catch-effort data. Robust estimation of parameters in the presence of several levels of clustering depended more on the choice of cluster definition than on the choice of correlation structure within the cluster. Models with smaller cluster sizes produced stable results, while models with larger cluster sizes, that may have had complex within-cluster correlation structures and that had within-cluster covariates, produced estimates sensitive to the correlation structure. The preferred model arising from this dataset assumed that catches from a vessel were correlated in the same years and the same areas, but independent in different years and areas. The model that assumed catches from a vessel were correlated in all years and areas, equivalent to a random effects term for vessel, produced spurious results. This was an unexpected finding that highlighted the need to adopt a systematic strategy for modelling. The article proposes a modelling strategy of selecting the best cluster definition first, and the working correlation structure (within clusters) second. The article discusses the selection and interpretation of the model in the light of background knowledge of the data and utility of the model, and the potential for this modelling approach to apply in similar statistical situations.

Original languageEnglish (US)
Pages (from-to)159-177
Number of pages19
JournalAustralian and New Zealand Journal of Statistics
Issue number2
StatePublished - Jun 2000
Externally publishedYes


  • Covariance
  • Fishing power
  • Generalized estimating equations
  • Overdispersion
  • Poisson
  • Spatial and temporal correlations

ASJC Scopus subject areas

  • Statistics and Probability


Dive into the research topics of 'A generalized estimating equations approach for analysis of the impact of new technology on a trawl fishery'. Together they form a unique fingerprint.

Cite this