As this year’s World Economic Forum on Africa came to a close on Friday in South Africa – the host of the next United Nations Framework Convention on Climate Change (UNFCCC) Conference of Parties (COP) in November-an overarching thread emerged for Africa to enhance economic growth in an integrated, sustainable, job-growing fashion: diversify its energy portfolio to include more energy from renewable sources.

While many wealthy countries have tried to reduce the use of plastic shopping bags, Bostswana and South Africa recently tried to do the same by charging for bags that were previously issued for free. This commentary describes recent research on these two countries that yielded some surprising results: the long-run effect of the price on plastic bag use was smaller than that in the short run, and the effect did not vary much across income groups.