The findings are summarized in figure 2.8. The role of electricity in contributing to economic growth seems to be stronger than that of all other forms of energy, as the finding of no causality is less frequent in the former case (just 14 per cent in one of the reviews and not at all in the other - figure 2.8) than in the latter (figure 2.7). A direction of causality from electricity to growth, or reciprocal causality between them, is backed by 63 per cent to 72 per cent of the studies. The conservation hypothesis is supported in 23 per cent to 28 per cent.