By Giel Ton, Dominic Glover

Giel Ton and Dominic Glover published the report ‘Improving Knowledge, Inputs and Markets for Legume Expansion: A Contribution Analysis of N2Africa in Ghana and Ethiopia’, They applied process-tracing to assess the contribution of the research programme N2Africa, which aimed to harness nitrogen fixation technologies.

Process tracing offers a structured way to verify causal inferences by critically reviewing the process and sequence of change. The analysis begins by inferring the existence of a causal claim by reviewing programme documents and eliciting the (implied) Theory of Change. The end product is an assessment of the available evidence to characterise the strength of the contribution claims, using ‘hoop tests’ (Figure). The figure illustrates the approach and indicates that a stronger contribution claim is linked to the passing through a smaller (more stringent) hoop. The hoop tests are ‘counterfactual thought experiments’, based on rigorous logical reasoning.

Figure: Hoop tests to assess the strength of the contribution claim

 Hoop tests to assess the strength of the contribution claim

Source: Authors’ own.

The evaluation focused on two case studies, in Ghana and Ethiopia respectively, which were considered by N2Africa stakeholders to be promising for replication or upscaling. In each case study, stakeholder interviews were used to answer five generic questions, which were designed to assess the strength of the contribution claim made by N2Africa:

  • Did the change occur?
  • Did it result from a process in which N2Africa support was used?
  • Can this support be considered as a necessary (non-redundant) causal factor for that process to have taken place?
  • If not, was it a necessary causal factor in accelerating or scaling of the outcomes?
  • Were there any other institutions or programmes that may have provided similar support to the change process, if N2Africa had not been present?

The report documents the evaluation process and summarises the findings. The study found convincing evidence that N2Africa contributed substantially to a process of technological upgrading of soybean production in northern Ghana, which, however, is still only weakly contributing to the expansion of soybean production in that region. In Ethiopia, there was clear evidence that N2Africa had made a decisive contribution to expanding the production and supply of legume inoculants, and had stimulated awareness of and demand for inoculants among small numbers of legume farmers. However, stakeholders believe that the market for legume inoculants has only reached a small fraction of its potential.

Partner(s): Institute of Development Studies