Nigeria, Sept. 20 -- Ordinarily, the decision by the policy committee of the Central Bank of Nigeria (CBN), at its September meeting, to clamp down on www.abokifx.com, a web portal that aggregates the naira's exchange rate at the parallel market would have been welcome. Coming on the heels of the apex bank's decision to excise Bureaux de Change (BDCs) from the domestic foreign exchange supply chain, this looked like a further signal of the CBN's new resolve to clean up the nation's foreign exchange market.

And not too soon. Over the last nine months, the naira has lost value against most traded currencies at a worrisome rate. In part, the economy's struggle to put behind it the debilitating effects of the coronavirus pandemic explains th...