【正文】 i and Poole, 1975). Thus, this finding serves to strengthen the relationship between energy and national ine in Tanzania. The implication is that energy shortages can seriously hinder economic growth and development. As indicated, the Fstatistic is not usually used as a measure of significance in the Granger test but we have used it to test whether the inclusion of past values in the regression enhances the significance of the whole regression. The Ftests for all the regressions were significant at the 5% level of significance. The figures in parenthesis are DWstatistics which were used to test for the presence of autocorrelation and the values indicate the absence of first order autocorrelation. The need for an instantaneous causality test follows from the observations made by Granger that if a dislocated sequence occurs in the data (ie if Y causes E to occur with one period lag, instead a two period lag was observed) it could result in 39。spurious causality39。. This will pound the problems of identifying the direction of causality, especially, a unidirectional one. Pierce and Hughes (1977) argue that the Granger type test cannot handle the problems of contemporaneous innovations39。 on one or all the variables used. Such innovations are always present in the field of technology not least energy. For example, effective conservation measures, efficient energy end use appliances and changes in the laws affecting transport and urban planning will affect energy intensity relative to economic activities. Accordingly, Pierce and Hughes (1977) suggested that one way of accounting for 39。contemporaneous innovation39。 is to test for instantaneous causality. Using this method, we have tested whether the inclusion of a current value of Y with its past values will provide a better prediction of current values of E and similarly if we are testing for instantaneous causality between E and Y. From the results shown in Table 3, the causality between energy and GNP is not instantaneous, but that between GNP and energy, GDP and energy as well as energy and GDP are instantaneous. This is not surprising since a dislocated sequence in energy consumption was unavoidable in the aftermath of the oil price increases in the 1970s. This had an adverse effect on GNP since more than % of the country39。s export proceeds went to oil imports in 1987, to the detriment of other equally vital sectors of the economy (Davidson, 1992). The instantaneous causal direction be tween energy and GDP and vice versa indicates the sensitivity of economic activities to energy consumption, as full utilization of economic capacity became dependent on fuel availability. The Fstatistics, as we explained in the case of the Granger test, are not usually required here as a test of significance but rely on the standard errors of the regressions. However, we used them to test the significance of current value of Y which we included in the equation. We can observe that they are significant at the 5% level. The Granger test results for Nigeria shown in Table 4, indicate that the causality between GDP and energy is simultaneous but nonexistent in the direction of GNP and energy and vice versa in direction of energy and GNP. Given the impact ofoii exports on ine, it is not surprising to find that GNP does not Granger cause energy consumption and vice versa. However, the results for the instantaneous functional form shown in Table 5 reveal an instantaneous causal relationship between energy and not just GDP but also GNP. Thus, as explained earlier, some contemporaneous changes are discernible in the case of Nigeria which mayhave affected the relative size of its GNP and GDP. Following the oil price hike of 1973, these indicators experienced a huge boost, which may have dislocated their trend. This may have accounted for some of the econometric estimation problems experienced. The manner in which the money was squandered on the one hand, and on the other, the massive and unprecedented corruption of the period, meant that not all of the oil export proceeds were repatriated back to the country. Thus, the incidence of instantaneous causality associated with the use of the GNP variable is not surprising. Similar contemporaneous occurrence apply in the case of Tanzania as explained above, but suffice to reintorate that this resulted mainly from a bination of high oil prices and adverse economic trends.Results and implications Evidently, the above empirical analysis strongly uphold our theorizing that energy consumption is plementary to growth in national ine. A close scrutiny of Africa39。s energy structure casts huge doubts on its ability to achieve sustainable economic growth and development, given its energy problems. Despite its huge mercial energy reserve (hydroelectricity, crude oil, gas and coal), percapitaenergy consumption ranked among the lowest in the world. Conventional or biomass energy (mainly wood and charcoal) account for more than 70% of total energy consumption whereas in Asia and Latin America, this source accounts for only 35% and 25% respectively (Davidson, 1992). While rural energy demand is totally met from this source, only 10% of urban population use mercial energy (Anderson and Fishwick, 1984). Given the role of urban population in economic growth Kahnet (1986), meeting urban energy needs is essential in sustaining this growth momentum. However, the peting demands on biomass from other sectors of the economy on the one hand, and on the other, the accelerating rate of depletion has resulted in severe energy shortages. The associated private and social costs are equally marked and have been dubbed the first energy crisis (Mazava, 1981). Combining this with a second energy crisis that has its origin from the 1973 oil price increases have left the continent with huge energy deficits, which is proving very difficult to bridge. In the mercial energy sector, shortages are abound. The principa