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Papers by khalil mhadhbi

Revue Des Regions Arides, 2008

La septoriose, maladie cryptogamique du ble, constitue une contrainte majeure au developpement de... more La septoriose, maladie cryptogamique du ble, constitue une contrainte majeure au developpement de cette culture dans notre pays. Ce travail a pour objectif d'evaluer le niveau d'infestation de la variete Nasr 99 vis-a-vis de cette maladie, de comparer son comportement par rapport aux autres varietes cultivees et d'etudier l'effet du precedent cultural sur le developpement de cette maladie. Cette etude a montre que la variete Nasr 99 presente un niveau de resistance satisfaisant a cette maladie par rapport aux varietes: Karim, Khiar et Razzak. Par ailleurs, l'etude de l'effet de trois precedents culturaux; legumineuse, ble et betterave sur la severite d'attaque de Septoria tritici a montre que les niveaux d'attaque les plus eleves ont ete enregistres au niveau du precedent cultural legumineuse ce qui montre l'importance de la teneur du sol en azote dans l'expression de la maladie.

Applied Economics, 2008

In this piece, we highlight some of the salient issues and controversies surrounding the relation... more In this piece, we highlight some of the salient issues and controversies surrounding the relationship between financial development and economic growth, from both the theoretical and the empirical fronts. We first discuss the controversies on the role of financial development in economic growth; and we then proceed to review the causal relationship between financial development and economic growth. We conclude that the relationship between financial development and economic growth is highly complex, and is dependent on a number of factors. Hence, the argument that financial development always leads to economic growth should be taken with extreme caution.

International Journal of Sustainable Economies Management, 2019

The article is an extension to the pricing models proposed by Jean Tirol that model the consumpti... more The article is an extension to the pricing models proposed by Jean Tirol that model the consumption of an environmental good. However, the different consumption patterns of this good, which is characterized by a taste parameter (two tastes or a continuum of taste); always verifying an imbalance between the profit of the monopoly (mainly natural); and the utility function of the consumer agent. Taxation on the price, in relation to consumer preferences, can ensure the objectives of an efficient management of a good which has variations in its physical nature. Moreover, a coefficient of variation in its nature, based on a scale of measurement, can achieve the convergence between economic and social objectives. The underlying results show that the consumer surplus is proportional to the variation between the average and marginal utility. In addition, maximizing monopoly profit provides a reasonable price that ensures social equity measures between the different users.

International journal of business analytics, May 12, 2023

This study aimed to assess the effect of the shadow economy on the finance-growth relationship in... more This study aimed to assess the effect of the shadow economy on the finance-growth relationship in Tunisia over the period 1984-2020. The authors used a nonlinear autoregressive distributed lags (NARDL) model to verify the impact of the informal economy as measured by Tanzi's method on the finance-growth relationship. The results suggest that in the long term, with a positive change at the level of the shadow economy, the effect of financial development on growth becomes negative. The opposite is also true. However, in the short run, asymmetric effect of the shadow economy is only detected on economic growth and not on the financial development-economic growth nexus. Indeed, the level of the informal economy has an important role in the Tunisian economy. The significant and positive impact of financial development on the economy is strongly influenced by the size of the informal economy.

HAL (Le Centre pour la Communication Scientifique Directe), May 27, 2017

The purpose of this paper is to revisit the Granger causal relationship between banking sector de... more The purpose of this paper is to revisit the Granger causal relationship between banking sector development and economic growth for forty developing countries in the period 1970-2012. In order to capture the different aspects of banking sector development, we develop two banking sector development indices and apply the panel bootstrapped approach to Granger causality testing approach properly taking into account cross-sectional dependence and heterogeneity issues. The empirical results show limited support for the supply-leading, demand-following and complementarity hypotheses. Our results also provide evidence as the causal relationship between banking sector development and economic growth exists in twenty five countries.

Journal of International Development, Dec 15, 2021

This paper tracks the financial growth in Tunisia over the period 1984–2016 with a special focus ... more This paper tracks the financial growth in Tunisia over the period 1984–2016 with a special focus on the shadow economy. Using Tanzi's measures, we worked on a nonlinear autoregressive distributed lag (NARDL) model to test the impact of the informal economy. The results suggest that the long‐run effect of the financial growth becomes negative if there is a positive change in the shadow economy and the opposite holds. While changes in the shadow economy have no significant influence on the links between financial development and economic growth in the short run, they play a significant role in the Tunisian economy in the long run.

International Journal of Business Analytics

Empirical Economics, Mar 27, 2019

This paper investigates the direction of causality between financial development and economic gro... more This paper investigates the direction of causality between financial development and economic growth in Low-income countries. We develop a new proxy for financial development that refers to the input of real resources into the financial system. The panel causality testing approach, developed by Kónya (2006), based on the Seemingly Unrelated Regressions and Wald tests with the country specific bootstrap critical values, is applied to the panel of twenty one Low-income countries for the period 1970–2012. Our findings support the supply-leading hypothesis, as many financial development variables lead economic growth in Benin and Zimbabwe. Our results also confirm for twenty one Low-income Countries suggesting that their financial development does not depend on economic growth.

This paper will discuss a new approach to studying finance-growth nexus, based on the production ... more This paper will discuss a new approach to studying finance-growth nexus, based on the production inputs. We analyze, from a panel of 93 countries (developed countries and least developed countries) over the period 1972-2012, the standard regress of economic growth as well as a new proxy for financial activity and interaction effects of the latter with catching up, education, and physical capital accumulation. The results of the Least Squares Dummy Variable estimator show that, from a global perspective, financial activity was beneficial for growth and development. The interaction between financial development and the standard explanation of growth is an appropriate characterization of the relationship finance-growth. Secondly, there are signs of a positive relationship between financial development of countries and its potential for catching up. Third, financial activity has led to additional benefits in countries with higher levels of adult literacy. Fourth, regardless of a possibl...

Dehydrogenation of ethane to ethylene in CO2 was investigated over CeO2/γ-Al2O3 catalysts at 700℃... more Dehydrogenation of ethane to ethylene in CO2 was investigated over CeO2/γ-Al2O3 catalysts at 700℃ in a conventional flow reactor operating at atmospheric pressure. XRD, BET and microcalorimetric adsorption techniques were used to characterize the structure and surface acidity/basicity of the CeO2/γ-Al2O3 catalysts. The results show that the surface acidity decreased while the surface basicity increased after the addition of CeO2 to γ-Al2O3. Accordingly, the activity of the hydrogenation reaction of CO2 increased, which might be responsible for the enhanced conversion in the dehydrogenation of ethane to ethylene. The highest ethane conversion obtained was about 15% for the 25%CeO2/γ-Al2O3. The selectivity to ethylene was high for all the CeO2, γ-Al2O3 and CeO2/γ-Al2O3 catalysts.

Tax policy is among the most common and relevant instruments in the toolkit of policy-makers when... more Tax policy is among the most common and relevant instruments in the toolkit of policy-makers when thinking about promoting growth, yet there is not compelling evidence regarding its effect in Tunisia. Using a variety of approaches, we measure firstly the optimal tax burden rate using Scully's static model and the quadratic model. For Scully's static model, gross domestic product is the dependent variable. For the quadratic model, growth rate is a dependent variable explained by tax rate in level and in square including dummy variables. Secondly and according to stationary and cointegration test results, we focus on the long-term effects on gross domestic product of the important taxes, namely tax revenue and private receipts including dummy variable. In this second study, we use a basic Scully model and we develop a vector error correction model technique. Our results show that optimal tax burden rate has to be situated between 12.8% and 19.6% of gross domestic product which...

SSRN Electronic Journal, 2017

This paper aims to estimate a willingness to pay (WTP) model from a Logit and Tobit regressions. ... more This paper aims to estimate a willingness to pay (WTP) model from a Logit and Tobit regressions. The purpose of these estimates is to study the behavior of Tunisian consumers following their consumption of drinking water by calculating the marginal and elasticities’ effects. Empirical results show that the differentiation intra and inter-physical nature of the quality of water supplied to a major consequence to cause reactions in the strategy for consumer consumption. Indeed, in case of poor or average quality households are paying nearly a WTP to benefit from improved quality. In case where the drinking water’s quality is not a problem of satisfaction among households, the payment of WTP will depend on the awareness’s level of the questioned agent. Therefore, households those who recognize the scarcity are paying nearly.

international journal of research in computer application & management, Jan 23, 2014

This study investigates the relationship between financial development and economic growth in the... more This study investigates the relationship between financial development and economic growth in the context of five South Asian countries for the period 1985-2014. Pedroni, Johansen co-integration, and panel based Granger causality tests are employed to examine the long and short run relationship dynamics between economic growth and other instrumental variables estimated in this paper. A vector autoregressive model (VAR) is a constructive method of analyzing the impact of a given variable on itself and all other variables by using variance decompositions (VDCs) and impulse response functions (IRFs). To check the robustness of this study, fully modified least square (FMOLS) has been conducted. The results of Pedroni and Johansen co-integration tests confirm that the indicators of financial development have a co-integration relationship with economic growth in the long run. Granger causality test shows that bidirectional causality between economic growth to M2 and also real interest rate and domestic credit to private sector in the short run. Moreover, unidirectional causality exists among the total value of stock traded variable to economic growth, M2 to domestic credit to private sector and M2 to real interest rate in the short run. This paper also documents shocks in stock traded total value has strongly positive response to economic growth. Shocks to domestic credit to private sector, trade openness, M2 have positive response with economic growth but not very strong. The shocks response function of real interest rate to economic growth is negative and quickly returns to the equilibrium. The results of variance decomposition confirm that shocks in the variables of M2 and stock traded total value shock have more impact on economic growth in the long run. FMOLS is employed to check the robustness and shows that financial development and economic growth are holding same relationship except the real interest rate. Policy makers should take immediate steps to minimize the interest rate spread in the south Asian countries. An optimum real interest rate spread will spur the growth process in the south Asian region. The policy makers also should think for transformation of the financial system through upgrading and strictly imposing the financial rules and regulations. The financial institutions must be monitored closely and the policy makers should pay more attention on that issue.

American Journal of Applied Mathematics and Statistics, 2014

This paper examines the causal relationship between financial development and economic growth for... more This paper examines the causal relationship between financial development and economic growth for 27 medium-income countries in the period 1970 to 2012. We develop a new proxy for financial development that refers to the input of real resources into the financial system and apply the panel bootstrapped approach to Granger causality. The results show, for three countries the findings support strong evidence on supply-leading hypothesis which implies that financial development induces economic growth and for six countries the findings support strong evidence on demand-following. Our results confirm for twenty one countries suggesting that their financial development does not depend on economic growth.

Macroeconomics and Finance in Emerging Market Economies, 2014

This article investigates short-run as well as long-run relationships, and also causality relatio... more This article investigates short-run as well as long-run relationships, and also causality relationships between banking sector development and the economic growth of India for which empirical analysis is performed using annual data. We use a new data set of banking sector development indicators to argue that banking sector development substantially affected economic growth. We find strong evidence that banking sector development caused economic growth in the Indian economy, especially in the period between 1960 and 2011, covering 52 years of the post-independence period for India.

Lupus, 2010

Livedoid vasculopathy is a rare condition which predominantly affects young women. It is characte... more Livedoid vasculopathy is a rare condition which predominantly affects young women. It is characterized by intense painful purpuric maculae in the legs, ankles and feet, due to thrombosis of the small and medium-sized dermal vessels, in the absence of vasculitis. Livedoid vasculopathy has been frequently associated with hypercoagulable states and antiphospholipid syndrome. We describe a 34-year-old White woman suffering from systemic lupus erythematosus, livedo reticularis, haemolytic anaemia, severe thrombocytopenia and recurrent venous thrombosis who was admitted to the hospital for extremely painful purpuric lesions in her lower limbs. The clinical and histological findings were diagnostic of livedoid vasculopathy. Once the initial sub-therapeutic international normalized ratio levels were corrected, livedoid vasculopathy did not recur. Tests for antiphospholipid antibodies were repeatedly negative. This case, the first reported of livedoid vasculopathy in a patient with seronegat...

Japanese Circulation Journal, 1993

Journal of International Development, 2021