Socio-technical change linking expectations and representations: Innovating thermal treatment of municipal solid waste

This paper combines two theoretical perspectives: future technological expectations mobilising resources, and social representations assimilating new ideas through anchoring onto familiar frames of reference. The combination is applied to the controversial case of thermal-treatment options for municipal solid waste, especially via gasification technology. Stakeholders' social representations set criteria for technological expectations and their demonstration requirements, whose fulfilment in turn has helped gasification to gain more favourable representations. Through a differential 'anchoring', gasification is represented as matching incineration's positive features while avoiding its negative ones. Despite their limitations, current two-stage combustion gasifiers are promoted as a crucial transition towards a truly 'advanced' form producing a clean syngas: R&D investment reinforces expectations for advancing the technology. Such linkages between technological expectations and social representations may have broader relevance to socio-technical change, especially where public controversy arises over the wider systemic role of an innovation trajectory.