Censored Quantile Regressions of Chronic and Transient Seasonal Poverty in Rwanda

It is crucial for social policy in Less Developed Countriesto identify correlates of poverty at the household level. Thishas been done in the literature by estimating household povertyequations typically with Tobit and Probit models. However, whenthe errors in these equations are non-normal and heteroscedastic,which is usually expected, these models deliver biased estimates.Using quarterly data from Rwanda in 1983, we reject the normalityand homoscedasticity assumptions for household chronic and transientlatent poverty equations. We treat this problem by estimatingcensored quantile regressions. Our results of censored quantileregressions and of inconsistent Tobit regressions are substantiallydifferent. However, in the case of chronic poverty the signsof the apparently significant coefficients are generally inagreement, while for seasonal transient poverty different variableshave significant effects for the two estimation methods. Oursecond contribution is to study, for the first time, correlatesof poverty indicators based on quarterly consumptions. Our resultsshow that in Rwanda different correlates are significant forchronic poverty and for transient seasonal poverty. The effectsof the main inputs (land and labour) are more important forthe chronic component of poverty than for the transient one.Household location and socio-demographic characteristics playimportant roles that are consistent with usual explanationsof poverty in the literature.     

Exponential Hedging and Entropic Penalties

We solve the problem of hedging a contingent claim B by maximizing the expected exponential utility of terminal net wealth for a locally bounded semimartingale X . We prove a duality relation between this problem and a dual problem for local martingale measures Q for X where we either minimize relative entropy minus a correction term involving B or maximize the Q -price of B subject to an entropic penalty term. Our result is robust in the sense that it holds for several choices of the space of hedging strategies. Applications include a new characterization of the minimal martingale measure and risk-averse asymptotics.     

Agricultural Trade Liberalisation in the 21st Century: Has It Done the Business?

Based on a novel, detailed, time‐consistent tariff database taking account of import protection developments in the agricultural sector since 2001, we propose a statistical decomposition of the changes in the various types of tariffs. The results show that the multilateral system has played a limited role in trade liberalisation over the period. Many countries have continued to apply much lower tariffs on agricultural products than their WTO ceilings. Moreover, there has been substantial unilateral dismantling of tariffs over the period, so that much of the liberalisation took place outside WTO and regional agreements. The number of regional trade agreements has surged, but their impact on applied agricultural tariffs has been limited. Finally, we investigate the tariffs, trade and production implications for food and agricultural products of two extreme scenarios in the future development of trade negotiations: an ambitious surge of regional agreements and a trade war within the WTO context.     

Current account sustainability in G7 and BRICS: Evidence from a long-memory model with structural breaks

In this paper, we extend the existing literature on current account sustainability by examining the relevance of long memory and structural breaks in modelling the dynamics of current account to gross domestic product (GDP) ratios in G7 and BRICS. Unlike standard unit root tests, which have low power, especially in cases where the series is characterized by a fractional process, the long-memory approach provides an exact measure of the degree of persistence. However, long-memory models are known to overestimate the degree of persistence of the series in the presence of structural breaks. We show that regime changes do exist in both the mean and trend of the current account to GDP ratios. Thus, we test persistence allowing for both smooth and sharp breaks. Our methodology also allows any number of sharp breaks, whereas standard unit root tests only permit either one or two breaks. Hence, our approach is more general and more robust to misspecifications caused by the omission of breaks than standard methods. We show that current accounts are sustainable in both groups of countries, with the G7 and South Africa displaying long-memory behaviour.     

On the proportionality of EU spatial ex ante coexistence regulations: Reply

Desquilbet and Bullock (2010) criticize some aspects of our analysis of the European Union’s (EU) spatial ex ante coexistence regulations (SEACERs) of genetically modified (GM) and non-GM crops presented in Demont et al. (2009). We argue that, besides misinterpreting some of our original arguments, the authors propose a policy analysis framework which is inconsistent with the main goal of the EU’s SEACERs. Their example incorrectly suggests that SEACERs play an additional role of regulating non-GM crop supply on the market. This would be inefficient from a policy economics perspective, especially in an open economy where global trade is taken into account. Therefore, we argue that analyzing flexibility of SEACERs in a market framework could lead to erroneous conclusions and in that case a simple farm level analysis such as presented in Demont et al. (2009) is preferred.