Cohesion or 'the solidarity that unites'

'My triptych as President of the European Commission was: the competition that stimulates, the cooperation that strengthens, and the solidarity that unites'
(Jacques Delors in an interview in Le Monde, December 3, 2009)
'Not only is the policy response in some measure determined by the problem definition, but this definition itself may be strongly influenced by what is conceived to be practicable in terms of policy response.This interaction, therefore, has produced a definition of urban deprivation that is compatible with practical policy expedients, and policy responses that give the impression of being solutions to the problem. Sadly, experience has shown both to be illusory.'
(John Edwards & Richard Batley, The politics of positive discrimination)

After reading Communications from the Commission or similar EU documents, modal citizens of the European Union may be 'lost in verbosity'. To them cohesion or solidarity may just sound like a perfume or a rockband...
Let us start from the EC Treaty. Article 2 summarizes nicely 'the European project'.
The Community shall have as its task, by establishing a common market and an economic monetary union and by implementing the common policies referred to in Article 3 and 3a, to promote throughout the Community a harmonious and balanced development of economic activities, sustainable and non-inflationary economic growth respecting the environment, a high degree of convergence, a high level of employment and of social protection, the raising of the standard of living and quality of life, and economic and social cohesion and solidarity among Member States (our emphasis).
This article promises many good things. But will they be delivered? And how do we know whether they have been delivered or not? In other words, how to measure the performance of the EU?