Slim Ben Youssef

The Role of Renewable Energy Consumption and Trade: Environmental Kuznets Curve Analysis for Sub‐Saharan Africa Countries

Based on the Environmental Kuznets Curve (EKC) hypothesis, this paper uses panel cointegration techniques to investigate the short and the long-run relationship between CO2 emissions, economic growth, renewable energy consumption and trade openness for a panel of 24 Sub-Saharan Africa countries over the period 1980-2010. The validity of the EKC hypothesis has not been supported for these countries. Short-run Granger causality results reveal that there is a bidirectional causality between emissions and economic growth; bidirectional causality between emissions and real exports; unidirectional causality from real imports to emissions; and unidirectional causality runs from trade (exports or imports) to renewable energy consumption. There is an indirect short-run causality running from emissions to renewable energy and an indirect short-run causality from GDP to renewable energy. In the long-run, the error correction term is statistically significant for emissions, renewable energy consumption and trade openness. The long-run estimates suggest that real GDP per capita and real imports per capita both have a negative and statistically significant impact on per capita CO2 emissions. The impact of the square of real GDP per capita and real exports per capita are both positive and statistically significant on per capita CO2 emissions. For the model with imports, renewable energy consumption per capita has a positive impact on per capita emissions. One policy recommendation is that Sub-Saharan countries should expand their trade exchanges particularly with developed countries and try to maximize their benefit from technology transfer generated by such trade relations as this increases their renewable energy consumption.

Renewable energy consumption and agriculture: evidence for cointegration and Granger causality for Tunisian economy

ABSTRACT This paper uses the vector error correction model (VECM) and Granger causality tests to investigate short and long-run relationships between per capita carbon dioxide (CO2) emissions, real gross domestic product (GDP), renewable and non-renewable energy consumption, trade openness ratio and agricultural value added (AVA) in Tunisia spanning the period 1980–2011. The Johansen-Juselius test shows that all our considered variables are cointegrated. Short-run Granger causality tests reveal the existence of bidirectional causalities between AVA and CO2 emissions, and between AVA and trade. There are short-run unidirectional causalities running from non-renewable energy and GDP to AVA and to renewable energy, and running from CO2 emissions to renewable energy. Interestingly, there are long-run bidirectional causalities between all considered variables. Our long-run parameters estimates show that non-renewable energy, trade and AVA increase CO2 emissions, whereas renewable energy reduces CO2 emissions. In addition, the inverted U-shaped environmental Kuznets curve (EKC) hypothesis is not supported. Our policy recommendations are to increase international economic exchanges because this gives new opportunities to the agricultural sector to develop and to benefit from renewable energy technology transfer. Subsidizing renewable energy use in the agricultural sector enables it to become more competitive on the international markets while polluting less and contributing to combat global warming.This paper uses the vector error correction model (VECM) and Granger causality tests to investigate short and long-run relationships between per capita carbon dioxide (CO2) emissions, real gross domestic product (GDP), renewable and non-renewable energy consumption, trade openness ratio and agricultural value added (AVA) in Tunisia spanning the period 1980-2011. The Johansen-Juselius test shows that all our considered variables are cointegrated. Short-run Granger causality tests reveal the existence of bidirectional causalities between AVA and CO2 emissions, and between AVA and trade; unidirectional causalities running from non-renewable energy and output to AVA and to renewable energy, and from CO2 emissions to renewable energy. Interestingly, there are long-run bidirectional causalities between all considered variables. Our long-run parameters estimates show that non-renewable energy, trade and AVA increase CO2 emissions, whereas renewable energy reduces CO2 emissions. In addition, the inverted U-shaped environmental Kuznets curve (EKC) hypothesis is not supported. Our policy recommendations are to increase international economic exchanges because this gives new opportunities to the agricultural sector to develop and to benefit from renewable energy technology transfer. Subsidizing renewable energy use in the agricultural sector enables it to become more competitive on the international markets while polluting less and contributing to combat global warming.

The dynamic interaction between combustible renewables and waste consumption and international tourism: the case of Tunisia

This paper employs the autoregressive distributed lag (ARDL) bounds methodological approach to investigate the relationship between economic growth, combustible renewables and waste consumption, carbon dioxide (CO2) emissions, and international tourism for the case of Tunisia spanning the period 1990–2010. The results from the Fisher statistic of both the Wald test and the Johansen test confirm the presence of a long-run relationship among the variables under investigation. The stability of estimated parameters has been tested, while Granger causality tests recommend a short-run unidirectional causality running from economic growth and combustible renewables and waste consumption to CO2 emissions, a bidirectional causality between economic growth and combustible renewables and waste consumption and unidirectional causality running from economic growth and combustible renewables and waste consumption to international tourism. In the long-run, the error correction terms confirm the presence of bidirectional causality relationships between economic growth, CO2 emissions, combustible renewables and waste consumption, and international tourism. Our long-run estimates show that combustible renewables and waste consumption increases international tourism, and both renewables and waste consumption and international tourism increase CO2 emissions and output. We recommend that (i) Tunisia should use more combustible renewables and waste energy as this eliminates wastes from touristic zones and increases the number of tourist arrivals, leading to economic growth, and (ii) a fraction of this economic growth generated by the increase in combustible renewables and waste consumption should be invested in clean renewable energy production (i.e., solar, wind, geothermal) and energy efficiency projects.

Absorptive Capacity, R+D Spillovers, Emissions Taxes and R+D Subsidies

We consider in this paper a duopoly competing in quantities and where�firms can invest in R&D to control their emissions. We distinguish between effort carried out to acquire first-hand knowledge (original R&D)and effort to develop an absorptive capacity to be able to capture part of the knowledge developed by rival. There are also free R&D spillovers between firms. We show that a regulator can reach the social optimal outcome by implementing a taxation and subsidy policy. The regulator subsidizes at a higher rate original R&D effort than its absorptive capacity counterpart when the free spillovers are high, and the contrary may occur when the free spillovers are low. When the cost of original research is lower than the one of absorptive research, or when the learning parameter of the latter is low, then the socially optimal level of original research is higher than the one of absorptive capacity. We have the opposite result when the cost of absorptive capacity is lower than the one of original research and when the learning parameter is high.

Transboundary Pollution and Absorptive Capacity

The impact of the investment in absorptive capacity on transboundary pollution is studied by considering two countries, each of them regulating a firm. Firms can invest in inventive research and in absorptive research to lower their pollution intensity. The absorptive research enables a firm to capture part of the inventive research made by the other one. We show that by means of adequate emission taxes, original and absorptive research and development (R&D) subsidies, regulators can reach the non-cooperative social optimum. Interestingly, we show that the investment in absorptive research enables non-cooperating regulators to better internalize transboundary pollution. The higher is the learning parameter of absorption, the greater is the proportion of transboundary pollution internalized. Therefore, it is recommended for the international community to make the patent laws more flexible and enabling learning from the research made by others more interesting. Moreover, the investment in absorptive R&D may lead to multiple equilibria necessitating non-cooperating countries to coordinate on an equilibrium, which constitutes an incentive for them to cooperate.

Cooperating and Non-cooperating Firms in Inventive and Absorptive Research

We consider a duopoly competing in quantity, where firms can invest in both innovative and absorptive research and development to reduce their unit production cost, and where they benefit from free spillovers between them. We analyze the case where firms act non-cooperatively and the case where they cooperate by forming a research joint venture. We show that, in both modes of play, there exists a unique symmetric solution. We find that the level of investment in innovative research and development is always the highest and that the efficiency of investment in absorptive research has almost no impact on the equilibrium solution.