Real exchange rate and asymmetric shocks in the West African Monetary Zone (WAMZ)

This paper examines real effective exchange rate (REER) responses to shocks in exchange rate determinants for the West African Monetary Zone (WAMZ) over the period 1980–2015. The analysis is based on a country-by-country VECM, and oil price, supply and demand shocks are identified using long run restrictions in a structural VAR model. We report significant differences in the response of REER to real oil price, productivity (supply) and demand preference shocks across these economies. In addition the relative contribution of these shocks to REER movements in the short and long run appears to be different across economies. Our findings suggest that the WAMZ countries are structurally different, and asymmetric shocks with inadequate adjustment mechanisms imply that a monetary union would be costly

Long-run determination of the nominal exchange rate in the presence of national debts: Evidence from the yen-dollar exchange rate

This paper develops an intertemporal optimization model to examine the determinants of the nominal exchange rate in the long run. The model is tested empirically using data from the Japan and the USA. The proposed theoretical specification is well supported by the data and shows that relative national debts as well as monetary and financial factors may play a significant role in the determination of the long-run nominal exchange rate between the yen and the dollar

An Empirical Analysis of the Nexus between Investment, Fiscal Balances and Current Account Balances in Greece, Portugal and Spain

We provide new evidence that current account balances in Greece, Portugal and Spain have become non-stationary after the adoption of the euro implying that there is no long-run stable relationship between savings and investment contrary to the Feldstein-Horioka puzzle. This can be taken as evidence of unsustainable current account balances and loss of solvency for the underlying economies. Using the ARDL methodology we also report a statistical association between fiscal balances and current account balances which implies that fiscal austerity can help these economies to reduce their current account deficits and restore their competitiveness. Our empirical evidence also suggests a particularly strong significant negative association between domestic investment and current account deficits. The magnitude of this latter effect may have important policy implications concerning the ways in which investment is financed to improve external competitiveness

The long-run determination of the real exchange rate. Evidence from an intertemporal modelling framework using the dollar-pound exchange rate

This paper develops a model of optimal choice over an array of different assets, including domestic and foreign bonds, domestic and foreign equities and domestic and foreign real money balances to examine the determination of the real exchange rate in the long-run. The model is tested empirically using data from the UK and the USA. The results show that all the coefficients of the model are right signed and significant and consequently financial assets may play a significant role in the determination of the real exchange rate

Metabolic-flux dependent regulation of microbial physiology

According to the most prevalent notion, changes in cellular physiology primarily occur in response to altered environmental conditions. Yet, recent studies have shown that changes in metabolic fluxes can also trigger phenotypic changes even when environmental conditions are unchanged. This suggests that cells have mechanisms in place to assess the magnitude of metabolic fluxes, that is, the rate of metabolic reactions, and use this information to regulate their physiology. In this review, we describe recent evidence for metabolic flux-sensing and flux-dependent regulation. Furthermore, we discuss how such sensing and regulation can be mechanistically achieved and present a set of new candidates for flux-signaling metabolites. Similar to metabolic-flux sensing, we argue that cells can also sense protein translation flux. Finally, we elaborate on the advantages that flux-based regulation can confer to cells

Clownfishes evolution below and above the species level.

The difference between rapid morphological evolutionary changes observed in populations and the long periods of stasis detected in the fossil record has raised a decade-long debate about the exact role played by intraspecific mechanisms at the interspecific level. Although they represent different scales of the same evolutionary process, micro- and macroevolution are rarely studied together and few empirical studies have compared the rates of evolution and the selective pressures between both scales. Here, we analyse morphological, genetic and ecological traits in clownfishes at different evolutionary scales and demonstrate that the tempo of molecular and morphological evolution at the species level can be, to some extent, predicted from parameters estimated below the species level, such as the effective population size or the rate of evolution within populations. We also show that similar codons in the gene of the rhodopsin RH1, a light-sensitive receptor protein, are under positive selection at the intra and interspecific scales, suggesting that similar selective pressures are acting at both levels

Effects of a fire response trait on diversification in replicated radiations.

Fire has been proposed as a factor explaining the exceptional plant species richness found in Mediterranean regions. A fire response trait that allows plants to cope with frequent fire by either reseeding or resprouting could differentially affect rates of species diversification. However, little is known about the generality of the effects of differing fire response on species evolution. We study this question in the Restionaceae, a family that radiated in Southern Africa and Australia. These radiations occurred independently and represent evolutionary replicates. We apply Bayesian approaches to estimate trait-specific diversification rates and patterns of climatic niche evolution. We also compare the climatic heterogeneity of South Africa and Australia. Reseeders diversify faster than resprouters in South Africa, but not in Australia. We show that climatic preferences evolve more rapidly in reseeder lineages than in resprouters and that the optima of these climatic preferences differ between the two strategies. We find that South Africa is more climatically heterogeneous than Australia, independent of the spatial scale we consider. We propose that rapid shifts between states of the fire response trait promote speciation by separating species ecologically, but this only happens when the landscape is sufficiently heterogeneous