This letter extends Elgar and Simpson's (1994) analysis on the working
of the Bridlington Principles to the analysis of the working of TUC v
oluntary policy with respect to mergers among affiliated unions over t
he period 1960-83. Univariate analysis is applied to microdata to inve
stigate the effectiveness of voluntary policy on mergers with respect
both to the implementation and to the achievement of the underlying ob
jectives of the policy. The results of the tests clearly show the achi
evement of the implementation of the policy in terms of when and how m
ergers occurred and the achievement of the policy objective of rationa
lizing the structure of affiliated unions; the results of the tests ab
out the achievement of the policy objective of reducing competition fo
r membership among affiliated unions are less conclusive. The results
of our analysis on mergers broadly confirm Edgar and Simpson's results
about the effectiveness of TUC voluntary policies.