Muller

Publications

Defining Poverty Lines As a Fraction of Central TendencyJournal articleChristophe Muller, Southern Economic Journal, Volume 72, Issue 3, pp. 720-729, 2006

We show under lognormality that when the Gini coefficient is stable over time, defining the poverty line as a fraction of a central tendency of the living standard distribution restricts the evolution of the poverty measures to stability. That is, poverty does not change if the Gini coefficient does not change. Moreover, when the Gini coefficient slightly changes, most of the poverty change can be considered a change in inequality. The consequences of using different poverty lines are then analyzed. Thus, important features in studies of poverty change based on these lines may result from methodological choices, rather than from economic mechanisms.

The Valuation of Non-Monetary Consumption in Household SurveysJournal articleChristophe Muller, Social Indicators Research, Volume 72, Issue 3, pp. 319-341, 2005

No abstract is available for this item.

Poverty and inequality under income and price dispersionsJournal articleChristophe Muller, Canadian Journal of Economics, Volume 38, Issue 3, pp. 979-998, 2005

We introduce an analytical framework for welfare analysis that accounts for changes in the joint distribution of prices and incomes by using parametric formulae of poverty and inequality measures. We propose statistical indicators for the levels, variabilities and a statistical link of price indices and nominal living standards, which are consistent with a bivariate lognormal model. Our analysis provides intuitive insight about the social welfare impact of economic shocks affecting levels, variabilities, and correlation of prices and incomes. The roles of price and income variabilities for poverty and inequality are exhibited, with the possibility of several variation regimes.

Price index dispersion and utilitarian social evaluationJournal articleChristophe Muller, Economics Letters, Volume 89, Issue 2, pp. 141-146, 2005

The living standard indicator in utilitarian social evaluation functions (USEF) is the ratio of a nominal living standard and a price index. We show that under weak association of price indices and nominal living standards and usual concavity conditions on utility functions, utilitarian social welfare increases with price index dispersion when the aggregate price level is superior to the arithmetic mean of price indices, and diminishes when it is inferior to the harmonic mean.

Human capital and wages in two leading industries in Tunisia: evidence from matched worker-firm dataJournal articleChristophe Muller and Christophe Nordman, Brussels Economic Review, Volume 48, Issue 1-2, pp. 183-208, 2005

From Tunisian matched worker-firm data in 1999, we study the returns to human capital in two leading manufacturing sectors. Workers in the IMMEE benefit from higher returns to human capital than their counterparts in the Textile-clothing industry. In the IMMEE firms, low wage workers experience greater returns to experience than high wage workers. The wage premium for on-the-job training (OJT) is substantial for both sectors. However, taking into account whether formal training is still ongoing at the time of the survey, our results clearly indicate that workers bear heavy costs for their training. Our analysis shows that OJT and education can be efficient channels of policies aiming at raising earnings for low wages as well as high wages workers. However, careful consideration of the industrial sector should accompany these policies since specific impact of education, experience, OJT are found in the studied sectors.

Two-stage quantile regression when the first stage is based on quantile regressionJournal articleChristophe Muller and Tae-Hwan Kim, Econometrics Journal, Volume 7, Issue 1, pp. 218-231, 2004

We present the asymptotic properties of double-stage quantile regression estimators with random regressors, where the first stage is based on quantile regressions with the same quantile as in the second stage, which ensures robustness of the estimation procedure. We derive invariance properties with respect to the reformulation of the dependent variable. We propose a consistent estimator of the variance–covariance matrix of the new estimator. Finally, we investigate finite sample properties of this estimator by using Monte Carlo simulations. Copyright Royal Economic Socciety 2004

Prices and living standards: evidence for RwandaJournal articleChristophe Muller, Journal of Development Economics, Volume 68, Issue 1, pp. 187-203, 2002

No abstract is available for this item.

Censored Quantile Regressions of Chronic and Transient Seasonal Poverty in RwandaJournal articleChristophe Muller, Journal of African Economies, Volume 11, Issue 4, pp. 503-541, 2002

It is crucial for social policy in Less Developed Countries to identify correlates of poverty at the household level. This has been done in the literature by estimating household poverty equations typically with Tobit and Probit models. However, when the 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 normality and homoscedasticity assumptions for household chronic and transient latent poverty equations. We treat this problem by estimating censored quantile regressions. Our results of censored quantile regressions and of inconsistent Tobit regressions are substantially different. However, in the case of chronic poverty the signs of the apparently significant coefficients are generally in agreement, while for seasonal transient poverty different variables have significant effects for the two estimation methods. Our second contribution is to study, for the first time, correlates of poverty indicators based on quarterly consumptions. Our results show that in Rwanda different correlates are significant for chronic poverty and for transient seasonal poverty. The effects of the main inputs (land and labour) are more important for the chronic component of poverty than for the transient one. Household location and socio-demographic characteristics play important roles that are consistent with usual explanations of poverty in the literature. Copyright 2002, Oxford University Press.

New markets, new opportunities? by Nancy Birdsall and Carol Graham (eds). (Washington, The Brookings Institution, 2000, pp. 331)Journal articleChristophe Muller, Journal of International Development, Volume 13, Issue 8, pp. 1201-1202, 2001

No abstract is available for this item.

The Properties of the Watts Poverty Index under LognormalityJournal articleChristophe Muller, Economics Bulletin, Volume 9, Issue 1, pp. 1-9, 2001

Under lognormality assumption, we derive the parametric formula of the Watts measure, one of the main axiomatically sound poverty measures. In these conditions, we derive new properties of the Watts measure, its sensitivity to distribution parameters and its parametric standard error.