Whenever a geophysical image is to be constructed, a variety of choices must be made. Some, such as those governing data selection and processing, or model parametrization, are somewhat arbitrary: there may be little reason to prefer one choice over another. Others, such as defining the theoretical framework within which the data are to be explained, may be more straightforward: typically…

In the last decade, China�s trade with Africa increased faster than its overall foreign trade. This article focusses on the role of real exchange rates in this growth. A �bilateral real exchange rate� augmented trade gravity model applied to China�s trade with 49 African countries over the period 2000�2011 shows that the real appreciation of most African currencies rel…

Adopting a model with two half-spaces that consist of solid and porous materials, we numerically investigate the seismoelectric conversion at the solid–porous interface. First, the wave fieldsinalow-porositytwo-layermodelarecomparedwiththoseinahomogeneousfull-space model. The consistency of seismic waves is a validation of our program. We are interested in the quasi-coseismic electromag…

The inverse problem for Earth structure from normal mode data is strongly non-linear and can be in herentlynon-unique. Traditionally, the inversion is linearized by taking partial derivatives of the complex spectra with respect to the model parameters (i.e. structure coefficients), and solved in an iterative fashion. This method requires that the earth quakes our cemodel is known. However…

The economic landscape of most African countries depends essentially on the dynamics of climate change. Key sectors driving their economic performance and livelihoods such as agriculture, forestry, energy, tourism, coastal and water resources are highly vulnerable to climate change. This article examines the empirical linkage between economic growth and climate change in Africa. Using annual da…

While much of the functional work on suction feeding has involved members of Acanthopterygii, an earlier cypriniform radiation led to over 3200 species filling nearly every freshwater trophic niche. Within the great majority of acanthomorph clades that have been investigated suction feeding and the underlying morphology responsible for the generation of rapid suction have been largely conserved…

This study uses new household data from Burkina Faso and regression analysis to further our understanding of household behaviour in relation to health care systems. We model the household decision-making process regarding health care utilisation in three steps: the perception of illness, choosing a treatment regime and health expenditure. In particular, we explain�at the individual lev…

We revisit a methodology to gauge the short-term effect of price changes on smallholder farmer�s welfare that is popular amongst policy makers and academia. Realising that farmers face substantial seasonal price volatility over the course of an agricultural year, we pay particular attention to the timing of sales and purchases. In addition we depart from the implicit assumption that all …

Exogenous shocks to farmers� consumption, production and labour market decisions are rarely considered accurately. For farm households, under labour market imperfections, such decisions are often interlinked. This calls for non-separable agricultural household models. According to this framework, second-order (or behavioural) effects include a direct (i.e., supply or demand reactions due …

This study investigates the relationship between family network density and income hiding in rural Liberia. We link people�s behaviour in a modified lottery experiment and a time preference game to detailed information about their family networks. We find that individuals with a dense family network are more likely to pay a fraction of their endowment to hide their earnings from the ex…