It has been argued that the perception and adjustment of particular costs and benefits provides the explanatory element which accounts for the differential impact of apparently similar barriers and opportunities within and between localities, tracers and arenas. Barriers and opportunities, identified in the previous chapter, appear less as determinants than as predisposing factors which variously impede or facilitate coordination.

As we have suggested at the end of the previous chapter, barriers and opportunities constitute a primary coordinative environment. They refer to those features which together form a basic context to interaction. Variations existed between the localities' primary environments as a consequence of our initial selection criteria. A secondary level of environmental variables is concerned with the less tangible features which relate more to process than to structural conditions. It is in relation to these process factors that cost and benefit considerations arise.

The rational planning approach to coordination takes little account of costs and benefits. The broadly based ‘pessimistic’ tradition which we identified pays such variables considerably more attention. The extensive literature of exchange theory which embraces bargaining and negotiation alongside power dependency conceptualisations, has such variables at its core. We constructed a number of ‘common sense’ questions around such theoretical bases. If, as this tradition would suggest, interaction is based upon the exchange or extraction of valued resources, then we might expect such interaction to be greatest when mutual benefits are likely, and least when no benefits are apparent to either party.