Cocoa marketing chain in developing countries: how do formal-informal linkages ensure its sustainability in Cameroon?

Open Access Article; Published online: 10 Oct 2020Although liberalization of the cocoa sector has increased internal competition within the marketing chain it has also led to the emergence of informal market actors within the chain. Therefore, the aim of this paper is to analyse how the cocoa marketing chain operates by measuring and comparing the marketing margins of the formal and informal actors. Qualitative data were used to establish the structure of the marketing chain and quantitative data to estimate the marketing margins. A total sampling size of 76 cocoa market actors was obtained by using a multi-stage sampling technique: 15 for qualitative data and 61 for quantitative data. Descriptive analysis was used to map the marketing chain and economic analysis to compute the costs and margins for both informal and formal market intermediaries from the Centre and South-West regions in Cameroon. The results indicated three market intermediaries (one informal and two formal) and four marketing channels by which cocoa moves from the farmers to the exporters. The calculation of marketing costs indicated that informal actors incurred the highest costs in both regions. The results regarding the marketing margins were twofold: informal actors obtain low net marketing margins when they do not use illicit strategies, but high net marketing margins when illicit strategies are used. Given the significant role of informal actors, we suggest that their actions should be integrated in a suitable manner into those of formal actors to contribute to a better performance of the marketing chain and to the sustainability of the cocoa sector

Phonons heat transport at an atomic well boundary in ultrathin solid films

A model calculation is presented for the heat transport across an extended atomic well boundary separating two ultrathin solid films, due to the phonons coherent elastic scattering at the boundary. Using the matching method, the transmission spectra are calculated for the phonons coherent scattering, for all propagating frequencies, and incident angles from inside the films, and for different boundary elastic conditions. The group velocities of the phonon branches in the ultrathin material films are explicitly calculated as a function of frequency and incidence angle. The model is applied to a corresponding gold material system, where the individual thermal conductivities for the phonon branches of this system are numerically evaluated for different boundary conditions. The results show that the heat transport at the boundary may be reduced or enhanced by controlling its elastic properties. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2011