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JAD Journal of African Development Spring 2008 Volume 10 #1 Table of Contents Disparities in Labor Market Outcomes across 11 Geopolitical Regions in Nigeria. Fact or Fantasy? Ruth Uwaifo Oyelere School Attendanca and Educational Enrollment 33 for Maternal Orphans in Zimbabwe: An Instrumental Variables Approach Craig Gundersen Thomas Kelly Examining the Trade-Growth Nexus in the Economic 51 Community of West African States Douglas K. Agbetsiafa Nutritional Health of the Children in Senegal: 71 A Comparative Analysis Marie Suzanne Badji Dorothée Boccanfuso BOOK REVIEW: Emigration, Brain Drain and Development: 105 The Case of Sub-Saharan Africa by Arno Tanner East-West Books Helsinki, Finland and Migration Policy Institute, 2005

EXAMINING THE TRADE-GROWTH NEXUS IN THE ECONOMIC COMMUNITY OF WEST AFRICAN STATES By DOUGLAS K. AGBETSIAFA 1 I. Introduction THE study explores the nature of the trade-growth nexus in order to determine the role of outward-oriented trade policies in raising economic performance in eleven member nations of West African Economic Community, hereafter referred to as Ecowas. Although existing studies in the literature have provided some important insights to the trade-growth relationship, a number of concerns about the conceptual and methodological approaches remain. First, many of the studies employed single equation ordinary least squares regression methodology to examine the relationship between openness to trade and economic growth, and are therefore, likely to suffer from simultaneous equation bias. Secondly, those studies that employed ordinary least squares regression analysis did so without examining the time series properties of trade and growth series. Indeed, Nelson and Plosser (1982) have shown that most macroeconomic time series data are nonstationary in their levels, but stationary when differenced. Thirdly, a number of these studies used cross-section data, thereby making it difficult to apply their findings to individual countries. Fourthly, most of the studies in extant literature concentrated on developed and developing regions of the world with little focus on the West African sub-region with its unique characteristics of low growth, high external indebtedness, and macroeconomic and structural imbalances. One of the objectives of the present study is to fill this gap in the empirical literature by providing evidence on the impact of outward-trade policies and economic development in eleven economies in the West African sub-region. The research evidence would be useful to policy makers in trade reforms designed to revive and sustain economic growth and development across Africa in general and the Ecowas region in particular. This is particularly important as development economists, policy makers, and governments of the region have embarked on serious efforts in integrating their economies. The paper employs recent advances in cointegration techniques and country-specific time series data to examine both short-run dynamics and 1 Douglas K. Agbetsiafa - School of Business & Economics, Indiana University South Bend, 1700 Mishawaka Avenue, South Bend, IN 46634 Tel: (574) 520-4208 Fax: (574) 520-4866 E-mail: dagbetsi@iusb.edu

52 JOURNAL OF AFRICAN DEVELOPMENT the long-run equilibrium relationship between trade and economic growth for eleven of the fifteen member states of Ecowas 2 for which complete and reliable data were available. It is worth noting that in 2003, African central bankers announced a plan for a single currency and common central bank for the entire continent, and regard regional economic unions including the Ecowas as an intermediate step toward a single African central bank and currency. A plan with such potential widespread economic and political consequences deserves a careful examination based on good research intelligence and analyses of the underlying growth dynamics and processes in each of the member countries in order to harness them for economic growth and development of the region. However, to date and to the present author s knowledge, very little research has been done on these aspects of the plan toward a single economic and currency union of Africa. The rest of the paper is organized as follows. Section II reviews the empirical literature on trade-growth nexus. Section III specifies the VEC model after examining the time series properties of the trade and growth variables. Section IV discusses the empirical results. Section V presents summary and policy implications. II. Survey of Literature The classical and neoclassical theory seeks to explain the benefits from trade by contrasting the likely outcomes that might prevail with free trade than with autarky. Central to the classical and neoclassical theory is the notion of comparative advantage that would lead to an efficient reallocation of international resources, largely due to specialization and division of labor. In the conventional theory, the gains from trade come from the import side. However, exports have an indirect but pivotal role as exports allow the country to buy imports of intermediate goods on more favorable terms than if produced at home (Meier, 1995, p. 459). The neoclassical theory is essentially supply oriented (Federici and Marconi, 2002), though the link between exports and growth can be traced from some earlier works. In his demand-oriented theory of growth, Kaldor (1970) identifies foreign demand as the ultimate constraint on growth in an open economy. In the staple theory of growth, extensive growth of export of primary or staple product having comparative advantage is regarded as a source of higher growth rates of output. The trade-led growth hypothesis has received its latest boost from the endogenous growth theory which identifies four major sources of growth, namely, (i) increases in accumulation of capital goods; (ii) improvements in the quality of the labor force; (iii) reallocation of resources from low to 2 Benin, Burkina Faso, Gambia (The), Ghana, Ivory Coast, Mali, Mauritania, Niger, Nigeria, Senegal and Togo.

EXAMINING THE TRADE-GROWTH NEXUS IN THE ECONOMIC COMMUNITY OF WEST AFRICAN STATES 53 high-productivity sectors; and (iv) technical change (Durlauf et al., 1996). The two basic differences between the new growth theory and the neoclassical theory are: (a) various social and economic policies are tipped to affect the growth rate in the new growth theory, while in the neoclassical theory, these policies affect only the level of real income not the growth rate; and (b) in the neoclassical theory, physical capital is deemed as a transitory source of growth as it is subject to diminishing returns, while in the new growth theory, both physical and human capital are assumed to exhibit increasing returns to scale. The source of increasing returns is knowledge, which is created by acquisition of skills through education and training, learning by doing and innovation or research and development (Grossman and Helpman, 1991). Aghion and Howitt (1992) hold that industrial innovations resulting in new and improved intermediate products have positive implications for changes in technology that in turn stimulate growth. Further, the secondary effects of learning by doing or investment in education may even exceed the direct effects on growth (Coe and Helpman, 1995). Grossman and Helpman (1991) describe interactions with the outside world as the most important mechanism for promoting innovation and growth in a small economy. The exchange of ideas can occur through personal contacts and use of imported intermediate products. Romer (1993) also holds a similar view. Roemer explains the poorness of a developing country in terms of its lack of physical objects such as factories, and roads (`Object gaps ) and lack of ideas or knowledge (`Idea gaps ) to create values compared to a developed country. An object gap is manifested in savings and capital accumulation while an idea gap includes insights about packaging, marketing, distribution, payment systems, quality control as well as the technology gap among others. An outward oriented trade policy inevitably involves interactions with foreign firms and agents and, hence, can help reduce the idea gaps. The conventional view of the trade-growth nexus argues that unidirectional causality runs from trade to economic growth. Proponents of this view include Helpman and Krugman (1985), Krueger (1985), Rodrik (1988), Vorvodas (1973), Afxentiou and Serletis (1992), and Yaghman (1994). A second view hypothesizes that unidirectional causality runs from economic growth to trade. According to this view, higher income growth facilitated by higher productivity would result in lower unit costs which would translate to higher exports. In the event that domestic production rises at a faster pace than domestic demand, producers will sell their goods in foreign markets. Proponents of this view include Kaldor (1967); Ghartey, (1993), Sharma and Dhakal, (1994). A third view argues that there can be bidirectional causality between trade and economic growth. Proponents of this view include Helpman and Krugman (1985); Kunst and Mann (1989); Ghartey (1993); Sharma and Dhakal (1994). According to a fourth view, there is no relationship between trade and economic growth. Pack (1992) contends that

54 JOURNAL OF AFRICAN DEVELOPMENT exports and economic growth are the outcome of many complex processes of development and structural change that occur in the economy. Support for the trade-led growth theory is not, however, universal. As Young (1991) argues, learning by doing effects may slow down at later stages of economic development and can even stop eventually if not reinforced by new technical progress. This echoes the general sentiment that in an uncertain world market, reliance on exports alone may not necessarily lead to a sustained long-term growth in a developing country and that the markets in the industrialized world may not be large enough to absorb these additional exports from the developing countries (Adelman, 1984; Cline, 1984). Furthermore, export promotion and import substitution policies may be complementary with the latter being a springboard for export-based growth (Hamilton and Thomson, 1994; Grabowski, 1994). The body of empirical literature investigating the relationship between a country s openness to trade and its economic growth is growing. A number of cross-country studies find that the ratio of exports to GDP or some other measure of openness is a significant determinant of growth. Yet, as Giles and Williams (2000) correctly points out, the focus of the debate is on whether or not a country is better served by orienting trade policies to export promotion or import substitution (p. 262). However, export promoting policies would cause an outflow of resources from import competing sectors of the economy to the export sector, and a resulting increase in imports. On the other hand, if import barriers are lowered, resources would flow out of the import competing sector into the export sector, and thereby promoting the export sector. The impressive growth performances of countries like Korea, Hong Kong, Singapore, Taiwan, Malaysia, Thailand, India and China have prompted many to place trade policy as a fundamental element of economic development planning (See, Krueger, 1998; Sachs and Warner, 1995). Rodrik (1998) examined the direct link between trade policy and income growth to determine how much of the variation in Africa s trade performance was attributable to terms of trade, geography, and economic policy. He finds geography, fiscal policy, and export taxation as important factors in explaining Africa s trade performance. He also tested for the impact of trade on the long-term growth of output in Africa, and found that growth could be explained by human resources, demography, and fiscal policy, but not trade policy. Based on this, evidence he concluded that within Africa, trade policies have had the expected strong effect on the volume and growth of trade, but have played a significantly smaller role in stimulating income growth than earlier results suggest. Hoeffler (1999) also fails to find any convincing evidence that trade influences the long-term growth rate in Africa. Applying panel data of African countries to an augmented Solow growth model over the period 1970 to 1995, Hoeffler finds that investment rate, educa-

EXAMINING THE TRADE-GROWTH NEXUS IN THE ECONOMIC COMMUNITY OF WEST AFRICAN STATES 55 tion levels, population growth, and initial output almost fully account for the observed growth of output. This result implies that the main impact of trade on long-term income growth can only occur indirectly through its impact on accumulation of human and physical capital. A study by Onafowora and Owoye (1998) also explores the relationship between trade and growth using a vector-error correction model that includes output, exports, investment and an indicator for trade policy for twelve African countries. Their goal was to determine whether export growth stimulated investment, thereby raising the rate of income growth. Results of their study show wide variations of statistical significance of the included variables as well as the explanatory power of the model across the twelve countries. The authors concluded that the export-led growth framework based on an explicit commitment to outward-looking policies and export expansion has had some success in some of the African countries. The preceding studies have shown that most empirical analyses of the relationship between trade and growth do not make allowance for possible indirect channels through which trade may be linked to economic growth. Recognizing the indirect channels may be accomplished by treating many of the system variables as endogenous. Recent research by Ndulu and Ndung u (1998) has moved in this direction. For example, they specify a simultaneous equations model that examines the effects of trade policies on export and import shares and how these variables are linked to income growth. They used panel data for selected African countries, a random effects estimation of single equations for export share, import share, and income growth, with explanatory variables as export and import prices; trade taxes; a measure for terms-of-trade shocks; indicators for the quality of institutions and civil unrest; changes in external debt; foreign direct investment; inflation; the ratio of investment to GDP; the real exchange rate; and lags of the trade shares. From each equation, they dropped the variables with insignificant coefficients in the random effects estimation. Using Full Information Maximum Likelihood (FIML), they estimated three equations as a system. Their results show that trade policies affect exports and imports, and thus output, indirectly through the real exchange rate. The co-authors also find that the influence of trade reforms is transmitted through the growth of investment, and that the growth of output and its lag do significantly affect the export and import shares. Other studies like Jung and Marshall (1985) reviewed a total of eleven empirical studies published between 1967 and 1982, and found them supporting the trade led growth hypothesis. In their review of the findings of 14 empirical studies published between 1977 and 1983, Greenaway and Sapsford (1994) found twelve of the studies supported the export-led growth hypothesis. Similarly, Giles and Williams (2000) compile more than 150 studies that include cross-country studies between 1963 and 1999 and time

56 JOURNAL OF AFRICAN DEVELOPMENT series studies between 1972 and 1999. Their results show that only four out of a total of fifty-seven cross-country studies show evidence of no significant causal relationship between trade and growth. Similarly, in only 10 of the 102 time-series studies, the findings indicate no clear causal relationship between exports and growth. In about as many cases, the evidence supports only the growth-led trade hypothesis. While other researchers like Chang et al. (2000) find no support for the trade-led growth theory for Taiwan, Hatemi-J and Irandoust (2000) find positive relationship between trade and growth for Ireland, Mexico and Portugal, and no causal relationship for Greece and Turkey. Other empirical findings that support the trade-led hypothesis include Ghirmay et al. (2001) with a finding of strong positive relationship between trade and growth for a number of developing countries, Greenway et al. (2002) who found positive impact of trade liberalization on the economic growth of the developing countries. The empirical evidence on the trade-growth relationship is clearly mixed, an indication that such a relationship is significantly more complicated than revealed in the standard single equation analyses. This condition provides an opportunity for more research to identify and understand both direct and indirect associations between trade and growth, inter-temporal effects, and the channels through which these effects are transmitted. III. Model, Data and Methodology Various measures of openness have been used in the literature. For example, while Romer et al (1989) used ratio of exports as a measure of openness to trade in testing the relationship between exports and economic growth for ex-post industrialized countries, Ram (1990) employed ratio of imports and Liu, Song, and Romilly (1997) used ratio of the sum of exports and imports as the indicator of openness. Romer (1993) argues that for time-series analysis, the imports/gdp ratio is generally acknowledged in the literature to be the best measure currently available. The present study employs all three measures of trade. Annual data for exports, imports and per capita GDP growth rate covering the period 1963 through 2003 were derived from various monthly issues of IMF s International Financial Statistics and the World Bank African Database. A prerequisite in applying the cointegration procedure is to test the unit root properties of the series. To this end, the paper uses both the Augmented Dickey-Fuller and Phillips-Perron unit root tests to determine the order of integration of the series. As cointegration is one of the important questions in the Vector Error Correction model (VEC), the next step is to estimate the long-run equilibrium relationship between each of the openness measures and per capita GDP growth rate utilizing the cointegration tests proposed by Johansen and Juselius (1988). It is known that cointe-

EXAMINING THE TRADE-GROWTH NEXUS IN THE ECONOMIC COMMUNITY OF WEST AFRICAN STATES 57 gration relationships are unstable in small samples (Berg and Borensztein 200a), but as Granger (1987) stresses, models estimated in first differences while the data are actually cointegrated will be misspecified (which will produce an omitted variable bias). Here the VEC model uses Maximum Likelihood (ML) method in the Johansen procedure to find cointegrating relationship(s) becomes essential, because in small samples ordinary estimation of cointegrating regressions becomes sensitive to the choice of the dependent variable. With the Maximum Likelihood method, this problem does not arise (Maddala 1992). Third, vector error-correction model based causality tests are implemented to ascertain the direction of causality between trade and economic growth. In conducting cointegration tests, the series are required to be non-stationary in their levels, and the cointegrating equation must have the same order of integration. Thus, before estimating the VEC model, the paper carried out diagnostic tests for unit roots by employing both the ADF and Phillip s- Perron tests for stationarity. The estimated equation takes the form: DX t 5ay1gX t-1 1d t 1S r i=1 UDX t-1 1e t (1) where, D is the difference operator, t is the time trend, and e t is the stationary random error, and the maximum lag length is p. The parameter of interest is g. If g = 0, the series contains a unit root. The cointegration procedure (Johansen, 1988; Johansen and Juselius, 1990) was applied in order to ascertain whether trade and economic growth are cointegrated for each of the eleven countries. The cointegration tests provide two likelihood ratio (LR) test statistics, the maximal eigenvalue (l-max) of the stochastic matrix, and the trace test statistics. For (l-max) and trace statistics, the null hypothesis is that H0: rk (P) = r against H1: rk (P) = r +1 and H0: rk (P) = r against H1: rk (P) r +1, respectively. Note that rk is rank, P is a matrix of long-run responses, and the matrix P has rank r, rk (P) = r. If the data cointegrated, P must be of reduced rank, r < N, where N is the number of variables. The paper employs both the trace and eigenvalue tests to determine whether r 1 cointegrating vectors are present in the system against the alternative hypothesis that the system is already stationary. The existence of at least one cointegrating vector in the system indicates the presence of causality between trade and economic growth. In order to test the causal relationship between trade and economic growth, it is common to apply the Granger causality test (see Granger 1969, and Sims 1972). Moreover, the cointegration technique pioneered by Engle and Granger (1987) and Granger (1986) makes a significant contribution towards testing causality. In this study, Granger causality test based on vector error-correction model is implemented. This procedure is preferred to the

58 JOURNAL OF AFRICAN DEVELOPMENT standard vector autoregressive model because it permits temporary causality to emerge from (a) the sum of the lagged coefficients of the explanatory differenced variables and (b) the coefficient of the lagged error-correction term. In addition, the error-correction model allows causality to emerge even if the lagged differences of the explanatory variables are not jointly significant (see Granger 1988, Miller and Russek 1990, Miller 1991, and Garcia and Zapata 1991). The error-correction model reintroduces the long-run information lost through differencing of time series data with unit roots as well as providing additional channel of Granger causality so far ignored by the standard causality tests of economic time series data. Following Granger (1969), variable (X) is said it Granger cause variable (Y) if and only if (Y) is predicted well using the past history of (X), together with the past history of (Y) itself, rather than by using just the past history of (Y). Accordingly, a bivariate vector error-correction model comprising trade and economic growth is represented in equations 2; D(Trd)5aZ t-11 S a i=1b i D(Trd) t-1 1S r i=1 D(Grw) t-1 1e t (2) D(Grw)5wZ t-11 S c j=1 1D(Grw) t-11s d j=1 l j D(Trd) t-1 1e t (3) where, Zt-1 represents the error correction term, the measures of openness to trade (Trd) are exports/gdp (Trx), imports/gdp (Trm), and (exports + imports)/gdp (Trt) respectively, and (Grw) is the growth of GDP per capita, a, b, c, d represent the optimal lags lengths obtained from the Akaike Information Criterion (AIC). In equation (2), the rejection of the null hypothesis that growth does not Granger cause trade requires that (i) the pi s co-jointly be statistically significant and/or (ii) the error correction term Zt-1 be statistically significant. Similarly, in equation (3), the null hypothesis that trade does not Granger cause growth is rejected if the li s are jointly statistically significant, and/or the error-correction term Z t-1 is statistically significant. IV. Empirical Results and Discussion Unit root results are summarized in Table 1. The null hypothesis of nonstationarity of the measures of trade and economic growth is tested against the alternative hypothesis of stationarity. Results of Dickey-Fuller (DF) and Augmented Dickey Fuller (ADF), and Phillips-Perron unit root tests for all eleven countries in the sample show that the annual levels of the variables are non-stationary while their first differences are stationary, with or without a deterministic trend. According to these results, the null hypothesis of unit root cannot be rejected for the trade and growth series at 5% significance level or better. On the other hand, the null hypothesis of

EXAMINING THE TRADE-GROWTH NEXUS IN THE ECONOMIC COMMUNITY OF WEST AFRICAN STATES 59 non-stationarity is strongly rejected for all variables in their first differences at better than 5% significant level or better. Table 1 Dickey Fuller and Phillips-Perron Unit Root Tests Results Trade and Growth (ECOWAS: 1963-2003) Levels First Difference Country Variable DF ADF P-P DF ADF P-P BENIN Grw -2.43-2.33-1.91-6.56-4.75 b -5.26 a Trx -2.64-2.72-2.49-5.38-4.93 b -4.20 b Trm -2.21-2.76-3.06-5.98-4.51 b -6.10 a Trt -2.89-2.95-2.89-5.00-4.76 b -4.96 b BURKINA FASO Grw -2.60-2.55-3.54-3.77-3.69 b -7.41 a Trx -2.07-2.33-2.58-4.60-4.49 b -8.35 a Trm -2.64-3.09-2.96-5.38-5.21 a -9.35 a Trt -2.34-2.78-2.60-5.11-4.97 b -9.3.7 a GAMBIA (The) Grw -1.40-1.46-1.92-3.83-3.75 b -6.46 a Trx -1.09-1.87 -.290-3.83-4.08 b -3.29 b Trm -2.88-1.83-2.27-3.45-3.40-3.46 b Trt -1.31-2.08-2.29-3.55-3.67 b -3.47 c GHANA: Grw -1.31-1.08-0.99-3.90-3.86 b -4.47 b Trm -0.60-0.13-0.36-4.61-4.47 ** -6.59 a Trm -1.04-0.78-8 -5.14-5.18 a -5.47 a Trt -0.67-0.72-0.23-3.82-2.96-4.62 b IVORY COAST Grw -1.43-2.40-2.42-3.72-3.67 b -3.71 b Trx -2.56-2.68-2.51-5.02-4.84 b -8.16 * a Trm -2.21-2.83-1.87-4.40-4.30 b -4.20 b Trt -1.57-1.94-1.90-6.39-6.23 a -6.23 a MALI Grw -1.96-2.10-2.11-5.27-5.15 a -5.11 a Trx -2.77-2.76-3.22-5.85-5.65 a -9.24 a Trm -2.80-2.45-2.96-6.67-6.55 a -9.57 a Trt -2.45-2.54-3.45-4.27-4.51 b -9.26 a MAURITANIA Grw -1.72-1.82-2.27-8.48-8.34 a -8.34 a Trx -2.36-2.36-2.32-6.92-6.71 a -7.03 a Trm -1.41-1.56-1.43-6.31-6.25 a -6.78 a Trt -1.56-1.70-1.49-7.39-7.22 a -8.79 a NIGER Grw -2.35-2.73-2.46-5.41-4.53 b -5.40 a Trx -3.50-2.19-3.57-8.67-6.16 a -9.16 a Trm -1.54-1.08-1.51-7.13-3.57 b -7.02 a Trt -2.14-7 -2.07 8.40-4.19 b -8.08 a NIGERIA Grw -1.90-1.56-1.06-4.02-4.62 b -3.94 b Trx -2.19-2.20-2.30-5.40-5.24 a -5.26 a

60 JOURNAL OF AFRICAN DEVELOPMENT Trm -5-2.02-1.47-3.65-3.62 b -3.60 b Trt -1.47-2.03-1.53-3.26-3.99 b -3.94 b SENEGAL Grw -3.66-2.21-3.52-7.47-5.46 a 8.32 a Trx -1.87-0.99-2 -8.25-4.89 b -9.00 a Trm -0.96-0.56-0.73-7.00 4.36 ** -7.18 a Trt -0.53-0.91-0.73-4.37-7.02 a -8.46 a TOGO Grw -1.30-2.98-1.14-7.26-1.07-6.76 a Trx -2.99-2.44-3.04-6.25-2.81-9.83 a Trm -2.20-2.38-2.25-5.22-2.10-8.83 a Trt -2.47-2.71-2.53-5.53-2.33-9.56 a Note: The MacKinnon (1991) critical values of the ADF at the 5% significant level is -3.53 and the critical value for the Phillips Perron statistics is -3.55. The letter a, b indicates the 1%, and 5%t significance levels respectively. Table 2 reports the results from the cointegration analysis in the VEC model for the eleven countries in the sample. Starting with the trace test statistic, the null hypothesis of no cointegration is rejected in all the eleven countries at the 5 percent significance level or better. The calculated trace test statistics range from a low of 16.12 in Ivory Coast (Trm) to a high of 43.98 in Niger (Trm). The l-max test results also reject the null hypothesis of no cointegration in favor of cointegration in all countries at the 5 percent significance level. The calculated test statistics range from a low of 12.98 in Ivory Coast to a high of 36.63 in Niger. The critical level is 12.98 at the 10 percent significance level for all countries. In sum, these results indicate the presence of one cointegrating relationship in all eleven countries, and suggest a long-run equilibrium relationship between trade and economic growth. The evidence of cointegration also implies that Granger causality must exist between each of the three measures of trade and growth series in at least one direction. The next section presents causality test results. Table 2 The Johansen Cointegration Results Null: r =0 Null: r 1 Country Variable Trace Maximum Trace Maximum Eigenvalue Eigenvalue BENIN Trx 23.14 a 21.58 a 1.55 1.55 Trm 25.34 a 17.45b 7.89 7.89 Trt 25.72 a 15.89b 9.83 9.83 BURKINA FASO Trx 27.89 a 22.43 a 5.47 5.47 Trm 35.18 a 27.39 a 7.79 7.79 Trt 29.82 a 29 a 8.43 8.43 GAMBIA (The) Trx 24.64 a 22.88 a 1.76 1.76

EXAMINING THE TRADE-GROWTH NEXUS IN THE ECONOMIC COMMUNITY OF WEST AFRICAN STATES 61 Trm 33.86 a 25.44 a 8.42 8.42 Trt 37.01 a 27.08 a 9.93 9.93 GHANA Trx 28.61 b 24.44 a 4.17 4.17 Trm 26.60 b 23.25 b 3.35 3.35 Trt 26.86 b 21.89 b 4.97 4.97 IVORY COAST Trx 31.00 a 23.00 a 7.99 7.99 Trm 16.12 b 12.98 c 3.13 3.13 Trt 22.73 a 13.63 c 9.09 9.09 MALI Trx 22.10 b 17.36 b 4.74 4.74 Trm 23.63 b 17.05 b 6.58 6.58 Trt 27.60 a 20.92 a 6.69 6.69 MAURITANIA Trx 26.29 a 21.98 a 4.32 4.32 Trm 31.39 a 28.21 a 3.18 3.18 Trt 31.39 a 28.21 a 2.73 2.73 NIGER Trx 21.78 b 13.87 7.90 7.90 Trm 43.98 a 36.63 a 7.38 7.38 Trt 32.89 a 24.73 a 8.16 8.16 NIGERIA Trx 34.96 a 31 a 4.95 4.95 Trm 35.46 a 32.65 a 2.81 2.81 Trt 33.51 a 32.12 a 1.39 1.39 SENEGAL Trx 30.59 a 16.57 b 1.42 1.42 Trm 23.01 b 18.25 b 4.75 4.75 Trt 26.01 a 16.04 b 9.96 9.96 TOGO Trx 26.69 a 26.42 a 0.27 0.27 Trm 22.53 b 19.26 b 3.27 3.27 Trt 24.73 a 17.25 b 7.47 7.47 Note: All calculations are carried out by Eviews 5.1. The letter a, (b or (c) indicates the 1%, 5%, and 10 % significance levels respectively. Interestingly, differing patterns of causality emerge from causality test statistics. When exports serve as the measure of trade openness, five countries, namely Burkina Faso, Ivory Coast, Gambia (The), Niger, and Nigeria show evidence of causality emanating from exports to growth and vice versa. In all countries, except Nigeria, the evidence shows that growth leads trade at the 5 per cent significance level or better with the error correction term and the lagged differences as the channels of causation. On the other hand, when imports serve as a proxy for trade openness, the evidence shows bidirectional causality in Ghana, Ivory Coast, Mali and Nigeria, and uni-directional causality from trade to growth in Mauritania, with the lagged differences as the main channel of causality in these five countries. In Benin, Burkina Faso, Gambia (The), Niger, and Senegal, causality runs from growth to trade, with the error-correction term as the major channel of causality. When total trade is used, results show bidirectional causality

62 JOURNAL OF AFRICAN DEVELOPMENT between trade and growth in Ivory Coast, Mali, Mauritania, and Senegal, and causality running from growth to trade in Benin, Burkina Faso, Gambia (The), Niger, Nigeria, and Togo at the 5 percent significance level or better. Table 3a Results of Causality Tests Openness does not cause growth Growth does not cause openness Country Series S b i= p D(Grw) t-1 Z t-1 S d j=1 l jd(trd) Z t-1 BENIN Trx 1.89 (.20) 2.12 (.16) 2.80 (.08) c 2.89 (.09) c Trm 0.70 (.51) 0.38 (.89) 0.12 (.88) 2.68 (.05) b Trt 4 (.30).000 (.94) 0.27 (.76) 3.23 (.05) b BURKINA FASO Trx 0.52 (.47) 3.95 (.01) a 3.07 (.08) b 0.14 (.93) Trm 8 (.33) 0.18 (.67) 2.75 (.05) b 5.83 (.02) b Trt 0.13 (.87) 0.28 (.59) 5 (.43 4.15 (.05) b GAMBIA (The) Trx 3.48 (.04) b 7 (.79) 9.42 (.01) a 1.58 (.21) Trm 8 (.19) 0 (.94) 1.30 (.30) 3.46 (.05) b Trt 2.38 (.11) 0.54 (.65) 2.97 (.06) b 2.97 (.05) b GHANA Trx 8 (.92) 0.38 (.68) 7.23 (.00) a 3 (.97) Trm 4.72 (.00) a 0.74 (.60) 5 (.09) c 3.77 (.01) a Trt 3 (.65) 0 (.98) 2.50 (.09) c 2.90 (.09) c IVORY COAST Trx 3.53 (.06) b 5 (.20) 0.20 (.65) 4.33 (.04) b Trm 4.09 (.02) a 2.33 (.11) 3.47 (.04) b 4.57 (.01) a Trt 2.69 (.05) b 1.38 (.26) 2.76 (.05) b 2.58 (.07) c MALI Trx 0.74 (.48) 0.19 (.97) 3.24 (.05) b 2.38 (.07) b Trm 0.60 (.55) 2.56 (.06) b 2.59 (.09) c 0.63 (.72) Trt 0.79) (.46) 2.76 (.05) b 2.99 (.06) b 1.84 (.16) MAURITANIA Trx 1.13 (.28) 0.77 (.47)` 3.23 (.05) b 2.12 (.10) c Trm 3.10 (.06) b 6 (.29) 2.18 (.13) 0.36 (.69) Trt 3.73 (.03) b 5 (.63)` 2.76 (.05) b 0.79 (.46) NIGER Trx 0.61 (.55) 3.85 (.03) b 4.22 (.02) a 0.53 (.58) Trm 0.26 (.85) 6 (.42) 4.99 (.05) b 3.22 (.02) a Trt 0.75 (.53) 0.51 (.53) 3.31 (.03) b 2.58 (.06) b NIGERIA Trx 7 (.62) 3.21 (.03) b 2.84 (.09) c 1.96 (.94) Trm 7 (.62) 3.21 (.03) b 2.85 (.05) b 1.96 (.14) Trt 2.41 (.09) c 1.93 (.16) 3.52 (.02) a 0.50 (.60) SENEGAL Trx 2.45 (.10) c 0.69 (.50) 6.91 (.00) a 0.57 (.56) Trm 0.37 (.69) 0.18 (.90) 3.53 (.00) a 3.91 (.01) a Trt 2.30 (.00) a 9 (.91) 7.50 (.00) a 9 (.91) TOGO Trx 0.28 (.75) 0.37 (.68) 3 (.96) 4.08 (.02) a Trm 0.23 (.79) 0.58 (.56) 1.19 (.31) 0.11 (.89) Trt 0.25 (.77) 1.99 (.12) 0.22 (.80) 2.82 (.04) b Note: 1). Z t-1 is the coefficient of the error correction term, and S d j=1 l jd(trd) t-1, S b i= p D(Grw) are the F statistics of the lagged independent variables. 2 The letter a, b, c indicates 1%, 5%, and 10% significance

EXAMINING THE TRADE-GROWTH NEXUS IN THE ECONOMIC COMMUNITY OF WEST AFRICAN STATES 63 levels respectively. The p-ratios are in parenthesis. Table 3b Summary of Direction of Causality in ECOWAS (1963-2003) A. One-way causality from Trade to Growth Ratio of Exports (Trx) Ratio of Imports (Trm) Ratio of Trade (Trt) Burkina Faso (5.2) Ghana (5.7) Ivory Coast () Gambia (The) (5.0) Ivory Coast () Mali (5.1) Ivory Coast () Mali (5.1) Mauritania (19.4) Niger (3.3) Mauritania (19.4) Senegal (4.9) Nigeria(5.3) Nigeria (5.3) B: One-way Causality from Growth to Trade Ratio of Exports (Trx) Ratio of Imports (Trm) Ratio of Trade (Trt) Benin (5.0) Benin (5.0) Benin (5.0) Ghana (5.7) Burkina Faso (5.2) Burkina Faso (5.2) Mali (5.1) Gambia (The) (5.0) Gambia (The) (5.0) Mauritania (19.4) Niger (3.3) Niger (3.3) Senegal (4.9) Senegal (4.9) Nigeria (5.3) Togo (3.0) Togo (3.0) C: Two-way causality from Trade to Growth (and vice versa) Ratio of Exports (Trx) Ratio of Imports (Trm) Ratio of Trade (Trt) Burkina Faso (5.2) Ghana (5.7) Ivory Coast () Gambia (The) (5.0) Ivory Coast () Mali (5.1) Ivory Coast () Mali (5.1) Mauritania (19.4) Niger (3.3) Mauritania (19.4) Senegal (4.9) Nigeria(5.3) Nigeria (5.3) Note: 1. Trx = Real Exports/GDP; Trm = Real Imports/GDP; Trt = Real (Exports + Imports)/GDP 2. Number in parentheses are the average real GDP growth rate during 2000-2006 Before presenting summary and conclusions of the study, model adequacy is discussed. Tests of residual serial correlation uniformly indicate that the errors are white noise. The column labeled LM in table 4 contains the marginal significance levels obtained in testing for the second order serial correlation using a Lagrange Multiplier procedure. 3 The results of a test of constant residual variance against the alternative of autoregressive conditional heteroscedasticity are reported under the column HET in table 4. 3 Engle (1982). The test has a power against a variety of heteroscedasticity alternatives.

64 JOURNAL OF AFRICAN DEVELOPMENT This null hypothesis similarly could not be rejected. Table 4 Tests of Model Adequacy Country Variables in Equations HET RESET LM S BENIN Grw and Trx 9.53 (.00) 2.52 (.60) 3.39 (.49) Grw and Trm 9.52 (.54) 2.25 (.50) 2.17 (.70) Grw and Trt 9.14 (.36) 9 (.32) 5.94 (.20) BURKINA FASO Grw and Trx 2.61 (.08) 1(.45) 1.40 (.82) Grw and Trm 0.75 (.47) 3.89 (.03) 2.90 (.57) Grw and Trt 1.03 (.36) 3.60 (.04) 2.27 (.68) GAMBIA (The) Grw and Trx 2.20 (.14) 8.61 (.01) 4.05 (.39) Grw and Trm 1.45 (.26) 2.80 (.04) 5.71 (.22) Grw and Trt 21.84 (14) 1.81 (15) 3.39 (.49) GHANA Grw and Trx 9 (.41) 4.24 (.01) 5.56 (.23) Grw and Trm 8.66 (.07) 6.98 (.00) 2.84 (.58) Grw and Trt 052 (.50) 3.53(.04) 5.51 (.23) IVORY COAST Grw and Trx 3 (.65) 9.25 (.00) 8.09 (.06) Grw and Trm 9 (.60) 9.78 (.00) 2.58 (.62) Grw and Trt 2 (.34) 9.96 (.00) 2.23 (.69) MALI Grw and Trx 0.56 (.86) 3.85 (.03) 2.99 (.56) Grw and Trm 1.36 (.30) 0.97 (.41) 2.49 (.64) Grw and Trt 7 (.31) 1.34 (.27) 2.10 (.71) MAURITANIA Grw and Trx 1.31 (.28) 4.23 (.02) 1.85 (.76) Grw and Trm 1.75 (.18) 1.13 (.33) 5.01 (.28) Grw and Trt 1.46 (.22) 2 (.49) 4.60 (.32) NIGER Grw and Trx 2.14 (.06) 1.32 (.27) 5.80 (.21) Grw and Tm 0.66 (.74) 9.39 (.00) 3.53 (.47) Grw and Trt 217 (.06) 2 (.49) 5.36 (.25) NIGERIA Grw and Trx 1.92 (.31) 2.61 (.04) 5.75 (.21) Grw and Trm 0.56 (.57) 2.20 (.14) 4.87 (.30) Grw and Trt 0.37 (.97) 5.43 (.01) 4.63 (.32) SENEGAL Grw and Trx 1.80 (.15) 3.01 (.06) 5.90 (.20) Grw and Trm 1 (.20) 3.25 (.05) 3.32 (.50) Grw and Trt 9 (.91) 1.50 (.22) 4.27 (.36) TOGO Grw and Trx 1.11 (.46) 2.44 (.05) 2.10(.71) Grw and Trm 1.49 (.23) 3.83 (.01) 2 (.80) Grw and Trt 1.38 (.28) 2.33 (.07) 3.88 (.42) Notes 1. White HET: Test for heteroscedasticity based on squared residual. 2. Ramsey RESET: tests for functional form misspecification. 3. LMS: Lagrange multiplier test for residual serial correlation 4. The marginal significance levels are shown in parentheses In order to examine whether a structural break occurred in the cointegration space of each country, a CUSUM break point test was implemented (See, Brown, Durbin, and Evan, 1975). This recursive estimation method

EXAMINING THE TRADE-GROWTH NEXUS IN THE ECONOMIC COMMUNITY OF WEST AFRICAN STATES 65 in the general form splits the sample into a base period, t=.3... k, and the model is estimated repeatedly adding one observation to the sample period until the sample period reaches t=t. In each estimation, the model parameters are updated and the plots of the series of the coefficients of the parameters are obtained after all possible estimations are worked out. This allows the evaluation of constancy problems through graphical representations. If the graphs of the coefficients display significant variations, the existence of a regime shift or instability in the period in question can be suspected. According to the CUSUM of squares tests, the residuals are within the critical 5% lines for Benin, Burkina Faso, Ivory Coast, Mali, Nigeria (Trt), and Senegal, and Togo as shown in figure 1. For the remaining countries (not shown) in figure 1, the recursive residuals pass the critical lines during the period, and suggest that a change in the economic regime and parameter instability as a result of famine, wars, coups, and structural adjustments. Finally, RESET tests reveal some evidence of model form misspecifica- Figure 1 Test for Regime Shift Benin (Trx) Benin (Trm) Benin (Trt) Burkina Faso (Trx) Burkina Faso (Trm) Burkina Faso (Trt) Ivory Coast (Trx) Ivory Coast (Txm) 1970 1975 1980 1985 1990 1995 1970 1975 1980 1985 1990 1995 1970 1975 1980 1985 1990 1995 2000 1970 1975 1980 1985 1990 1995 2000 Ivory Coast (Trt) Gambia (Trx) Mali (Trx) Mali (Trm) 1970 1975 1980 1985 1990 1995 2000 1970 1975 1980 1985 1990 1995 2000 1970 1975 1980 1985 1990 1995 1970 1975 1980 1985 1990 1995 Mali Trt)) Nigeria (Trx) Senegal (Trt) Togo (Trt) 1970 1975 1980 1985 1990 1995 1970 1975 1980 1985 1990 1995 1970 1975 1980 1985 1990 1995 1970 1975 1980 1985 1990 1995 2000 Note: All the calculations are carried out by Eviews 5.1, a statistical package by QMS (2004).

66 JOURNAL OF AFRICAN DEVELOPMENT tion bias in parameter estimates, except in Benin, Mali, Mauritania, Niger, Niger, Senegal and Togo. Two important conclusions emerge from these results. First, according to the tests of structural break point and parameter stability, CUSUM test results suggest the constancy of the integration space in six of the eleven countries, and implies e stable long-run equilibrium relation between trade and growth in these countries but unstable in the remaining five countries. However, the combination of positive and successful diagnostic tests suggests a good model performance. V. Conclusions The paper applies a vector error-correction model to West African data in order to examine the long-run equilibrium relationship between trade openness and growth, and their causal relationship in eleven members of the Economic Community of West African States. Among the research findings are first, existence of a steady-state, long-run relation between trade and growth in majority of the countries based on the Johansen cointegration results both the trace and the maximal eigenvalue (l-max) test statistics reject the null hypothesis of no cointegration in all eleven countries at the 5 percent significance level or better. Second, Granger non causality tests suggest differing patterns of causality. Causality tests suggest a bidirectional causality between trade (Trx) and growth in Burkina Faso, Gambia (The), Ivory Coast, Niger, and Nigeria; a unidirectional causality from growth to trade (Trx) in Benin, Ghana, Mali, Mauritania, Senegal and Togo. When imports (Trm) is the measure of trade openness, the evidence shows bidirectional causality between trade (Trm) and growth in Ghana, Ivory Coast, Mali, Mauritania and Nigeria; uni-directional causality from growth to trade(trm) in Benin, Burkina Faso, Gambia (The), Niger, and Senegal. With total trade (Trt) as a measure of openness, the evidence supports bidirectional causality in Ivory Coast, Mali, Mauritania, and Senegal; a oneway causality running from growth to trade (Trt) in Benin, Burkina Faso, Gambia (The), Niger, Nigeria and Togo. In sum, trade (using all three measures of openness) appears to have a positive impact on growth in all eleven countries, except Benin and Togo; while growth has a positive causal impact on trade openness. These different patterns of causality are consistent with findings by other researchers such as Grossman and Helpman, 1991; Bhagwati, 1988; Sachs and Warner, 1997; Onafowora and Owoye, 1998; and Fosu, 1990 and Ghartey (1993). Results are also consistent with the notion that openness influences a developing country s growth of GDP per capita by impacting the level of export and import activities and economic growth. Furthermore, trade may lead to improvement of each country s growth rate by allowing importation of capital and intermediate goods, and facilitating the transmission of knowledge which can be used to adapt and imitate developed country products.

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