Institutional Market Power in Comté: Insights from a ‘Double Marginalisation’ Model

This article explores the economic efficiency of a horizontally and vertically coordinated industry where upstream producers are atomised, but downstream processors are few, explicitly considering participation incentives and allowing the coordinated industry to exert market power towards buyers. The model offers insight into the probable social impacts of the government‐sanctioned supply control scheme in place in the French Comté cheese market, suggesting it falls short of constituting a Pareto‐improvement compared with a laissez‐faire situation. More generally, our theoretical model provides guidance to identify instances where encouraging industry coordination may be socially desirable. We formally introduce the concept of ‘seller‐equivalent degree of overall market power’ of the separated industry, a market characteristic comprised of measurable or inferable parameters, the value of which is shown to determine the potential for Pareto improvements through industry integration.     

Can farmers extend their cultivation areas in urban agriculture? A contribution from agronomic analysis of market gardening systems around Mahajanga (Madagascar)

The rapid urbanization in developing countries implies an increasing pressure on urban agriculture for production. As most perishable food products come from this agriculture in close proximity to population concentrations, we analysed from an agronomic point of view how market-garden farmers can meet this increasing urban demand. This work took place in the case of Mahajanga, a secondary city with high increasing demographic rate on the Northwest coast of Madagascar. Based on preliminary surveys to characterize the farming systems (on a sample of 91 farms), 11 market-garden farmers chosen in the three main agricultural zones of the urban area were surveyed during two years. Surveys aimed at understanding their decision rules in crop choices, crop allocation to land and resource management, and to estimate their room for manoeuvre to increase their leafy vegetable areas under cultivation. The wholesalers and retailers who buy the farmers’ produce were also surveyed. A previous model of decision rules regarding crop location on farm territory was used to analyse the on-farm surveys and cartographic methods (GIS and on-farm manual representations) were used to quantify the land use. We highlight the following major points. (1) The leafy vegetable production in the surveyed farms already intensively uses land: farmers have complex decision rules largely depending on the water dynamics in the two main environments (lowlands and lakesides) where leafy vegetables are cultivated during the dry season. (2) The scarcity of farmers’ resources (labour money and water) leads to very little internal room for manoeuvre to increase the leafy vegetable production in the farms. (3) At territorial level however, some land reserve exist in one of the lowlands, but not on lakesides. The water availability for agriculture must be better informed through specialized hydrologic studies, as one of the main constraints nowadays to extend the agricultural area. An extrapolation to other cases of urban agriculture is then discussed as well as the role of agronomy to help urban planners to consider the place of agriculture in the urban development.     

Major fire in a steam-methane reformer furnace

Causes of a major fire which resulted when a pigtail ruptured on a 10-year old hydrogen plant reformer and led to the destruction of 54 catalyst tubes.     

Correlation of acid gas-ethanolamine equilibrium using ionic concentrations

Experimental equilibrium measurements are modeled using a Davies-like ionic strength correction term for the reaction equilibrium constants. Calculated and experimental results are in much better agreement when the ionic strength correction terms are used.     

Measuring a Consumer Energy Conservation Ethic: An Analysis of Components

An energy future based on conservation will require that consumers subscribe to a Consumer Energy Conservation Ethic. This study identifies the components and best predictors of a conservation ethic.     

The interaction of shock waves in cylindrical structures

An experimental investigation into the validity and use of the hydraulic jump analogy for studying the interaction of shock waves in air with cylindrical structures.