Are grain markets in Niger driven by speculation?

Over the last two decades, millet prices in Niger have enjoyed periods of spectacular increase during which they seem to go well above their fundamental value. These episodes of price bursts followed by rapid reversals could be attributed to the presence of rational speculative bubbles. Considering millet as a food asset we have developed a pricing model, and tested for the presence of periodically and partially collapsing bubbles for 15 millet markets in Niger. The test strategy consists of estimating the fundamental value of millet and investigating the dynamic properties of price deviations from fundamentals. A battery of unit root tests aimed at controlling for skewness and kurtosis, and for non linearity in the bubble process, is implemented. These tests do not reject the presence of rational bubbles for some of the sample markets, and allow the identification of expanding and collapsing phases in bubble processes. The results show that small markets, located in deficit and remote areas are more prone to speculation than large markets in the main producing and consuming regions.periodically collapsing bubbles, M-TAR, Markov switching ADF, Residual Augmented ADF test, Rolling ADF test, millet

Taxing the urban unrecorded economy in sub-Saharan Africa

The global public revenue level of numerous African countries is low and the tax burden is highly concentrated on modern sector firms. One of the most current explanations for the low level of public revenue is the under-taxation of the urban unrecorded activities. The aim of this paper is to define an appropriate strategy in order to collect additional public resources from unrecorded activities in Sub-Saharan African Countries. In order to define an adapted taxation strategy for the unrecorded sector, informal micro-activities are distinguished from tax evasion activities (TEA). In Africa, the expansion of informal micro-activities is not fundamentally determined by their ability to evade taxes. On the contrary, the expansion of TEA, which are composed of large and small scale firms, is strongly linked to tax fraud (internal taxes, customs duties, etc.). The fundamental justifications of taxing the unrecorded activities differ according to the components of the unrecorded sector. Tax enforcement for TEA should produce substantial additional tax revenues and safeguards the durability of the tax collection system. With regard to informal micro-activities, taxation could be a significant tax revenue objective for local governments only and not for the central government. We examine the results of the measures aimed at taxing the unrecorded sector in some sub-Saharan African countries (Benin, Burkina Faso). Then, specific strategies are proposed in order to tax the informal micro-activities and TEA respectively. These strategies imply some specific tax measures widely implemented in Sub-Saharan African countries, such as a withholding tax profit. Some new measures, in particular a drastically simplified business tax for informal micro-activities, could be useful. With respect to tax collection, some innovative choices are suggested.

Alert at Maradi: Preventing Food Crises in West Africa by Using Price Signals

The aim of this paper is to exploit grain price data to detect the warning signs of looming food crises in Mali, Burkina Faso and Niger. Firstly we identify which markets play a leading role at the national and regional level. The second step consists of identifying crisis periods and characterizing price movements during the period proceeding a crisis. This analysis leads to the identification of early warning indicators whose relevance is tested using panel data qualitative choice models. The results show that monitoring price movements on "leading markets" during crucial periods of the year can help in forecasting future crises.Food security, Africa, Niger, early warning systems, discrete choice panel model, Food Security and Poverty, Q18, C25, D40, O18,

Alert at Maradi: preventing food crisis using price signals

National early warning systems of Sahelian countries are mainly based on biophysics models to predict agricultural production shortages and prevent food crisis. The objective of this paper is to show that cereal market prices also bring useful information on future food availability that could complete current early warning disposals. Indeed, at any point in time prices are informative not only on the state of present food availability but also on agents' expectations about future availability. The research is based on the exploitation of the statistical properties of price series. It aims at detecting movements in the prices trend signalling a coming crisis. We first identify markets playing a leading role in price formation at the national and regional level through the estimation of VAR models. The second step consists in identifying crisis periods and then the price shocks characterises during the period which precedes a crisis. This analysis leads to the identification of early warning indicators whose relevance is tested using panel data qualitative choice models. The data set encompasses 50 markets belonging to three countries: Mali, Burkina Faso and Niger, over the period 1990-2008. The results show that past price shocks on a few number of leading marketplaces can help preventing coming crises.Food security ; Sahel ; grain markets ; early warning systems ; discret choice panel model

Price Transmission in the Cocoa-Chocolate Chain

There is a common perception among consumers that the retail prices respond faster to an increase in the price of raw material than to a decrease. This paper aims at testing the existence of such asymmetric price transmission in the cocoa-chocolate chain on the French market. Two types of asymmetry are suspected: asymmetry in the transmission of positive and negative shocks that may reflect non-competitive behaviour in the chocolate industry and asymmetry in the transmission of small and large shocks that may be due do adjustment costs. These hypotheses are tested using the two-step approach to cointegration of Engle and Granger extended to encompass possible asymmetric adjustment to disequilibrium. Estimates indicate that a three-regime error correction model is the most appropriate. On the one hand, the chocolate price does not adjust to small shocks in the cocoa market. On the other hand, the speed of adjustment is larger for negative deviations than for positive ones. Les consommateurs ont souvent l’impression que les prix de détail répondent plus vite aux augmentations du prix de la matière première qu’aux baisses. Aussi, l’objectif de ce travail est de tester l’existence d’une transmission asymétrique des fluctuations de prix entre la matière première, la fève de cacao, et le produit fini, la tablette de chocolat sur le marché français. Deux formes d’asymétrie, ayant chacune une origine différente, sont recherchées : d’une part, une asymétrie dans la transmission des chocs positifs et négatifs, potentiellement liée à l’exercice d’un pouvoir de marché des industriels, et d’autre part, une asymétrie dans la transmission des grands et des petits chocs de prix liée à la présence de coûts d’ajustement. Les résultats, obtenus à partir d’une modélisation TAR du déséquilibre de prix par rapport à leur valeur de long terme, ne permettent pas de rejeter ces hypothèses. Sur la plus grande partie de la période couverte (1960-2003) le prix de la fève et le prix de la tablette évoluent indépendamment l’un de l’autre. Toutefois, au moment du boom du cacao (fin 70) le prix de la tablette répond rapidement à la hausse des cours de la fève tandis qu’à la fin des années 80, alors que le prix de la fève est retombé à un bas niveau, le prix de la tablette revient lentement vers l’équilibre.  modèle TAR, transmission de prix asymétrique, cacao

Price Transmission in the Cocoa-Chocolate Chain

There is a common perception among consumers that the retail prices respond faster to an increase in the price of raw material than to a decrease. This paper aims at testing the existence of such asymmetric price transmission in the cocoa-chocolate chain on the French market. Two types of asymmetry are suspected: asymmetry in the transmission of positive and negative shocks that may reflect non-competitive behaviour in the chocolate industry and asymmetry in the transmission of small and large shocks that may be due do adjustment costs. These hypotheses are tested using the two-step approach to cointegration of Engle and Granger extended to encompass possible asymmetric adjustment to disequilibrium. Estimates indicate that a three-regime error correction model is the most appropriate. On the one hand, the chocolate price does not adjust to small shocks in the cocoa market. On the other hand, the speed of adjustment is larger for negative deviations than for positive ones.modèle TAR;transmission de prix asymétrique;cacao

Impact of climate related shocks on child's health in Burkina Faso

The aim of this paper is to estimate the impact of weather related income shocks on child health in rural Burkina Faso where rain fed agriculture is the dominant production system. We combine health data originating from the 2008 household survey with meteorological data to define shocks at the child level. We first estimate the marginal effect of rainfall at various ages on the child's health in order to identify the critical period during which deprivation has the most severe consequences. Then we look for a different impact of shocks on girls and boys that would reflect a gender bias in intra household resource allocation. We also assess the household ability to smooth consumption by testing for an asymmetric effect of rainfall shocks according to their size and by testing the impact of shocks according to household endowments. Results evidence a strong relationship between rainfall shocks during the prenatal period and child health. Households are not able to dampen small but negative rainfall shocks. Unexpectedly, girls are less severely affected by shocks than boys. The robustness of results is tested by using the sibling and difference-in-differences estimators as well as placebo regressions

Preserving vertical co-ordination in the West African cotton sector

In this paper, we defend the idea that in the African context, non-market co-operation between farmers and ginning companies outperforms market transactions. In the absence of a reliable legal mechanism, market liberalization threatens the sustainability of contractual agreements between farmers and cotton companies. We present alternatives to the full market competition option and to the public monopoly organization that allow the production contract to be preserved. Special attention is paid to the case of Burkina Faso where efficiency gains have been obtained thanks to the strengthening of farmers' organizations and their financial participation in the cotton company.yardstick competition, zoning –, markets failure –, Contract farming –, West Africa –, Cotton –

Le paradoxe de la fiscalité agricole en Afrique Sub-saharienne

In many sub-saharan african countries, agricultural sector adjustment programs failed to succeed because of a severe budgetary constraint which prevent actual reform of the incentive scheme and lead to maintain a high degree of taxation on agricultural exports. On the basis of theoretical litterature and african agricultural sector specificities, the aim of this paper is to draw the main caracteristics of a tax policy for the agricultural sector which would enhance agricultural growth. It is suggested to replace export tarifs by a tax on agricultural income collected at the border, to introduce a land tax in the most favorable areas, and to keep agricultural inputs free from any taxation

The effect of devaluation on cattle markets integration in Burkina Faso

The aim of this paper is to highlight an aspect of devaluation that is generally ignored in the literature, namely, its positive impact on domestic trade. We develop a parity bounds model for cattle markets of Burkina Faso with two regimes of prices, autarkic and integrated, consistent with spatial and inter-temporal arbitrage conditions. When markets are autarkic, prices follow a random walk and when markets are integrated, prices are equal up to transaction costs. The integrated regime is more likely when transaction costs are low. In our model, the 1994 franc CFA devaluation reduces transaction costs relatively to cattle prices, thereby promoting markets integration. The model is tested using a switching regression with exogenous selection variables. The results show that the probability of market integration significantly increased after the devaluation.panel data., switching regression model, burkina faso, franc CFA devaluation, cattle, inter-temporal arbitrage, Market integration