This year, the report's key Investment Risk Index (IRI) expanded to cover 99 jurisdictions, providing ratings across five core areas of mining-related risk: Legal, Governance, Social, Fiscal and Infrastructure.

Head of Aspermont research and intelligence Chris Cann said the relevance of robust risk management tools had increased since the publication of last year's report.

"Though we were without the major risk-related events that punctuated the previous outing - think seismic alterations to the DRC's mining code and Tanzania's very public dispute with Barrick Gold - the overall mood in terms of global risk has darkened," he said.

"Compared to the 3.2% drop this year, the net move over the IRI's brief, three-year history is down 1.6%, which is probably a reasonable reflection of a risk dynamic for the mining industry that continues to drift."

There were just three AAA-rated jurisdictions this year, compared with eight in 2017.

Cann said Asia was "the standout this year" in logging a net positive result among its jurisdictions.

"The greatest disappointment, however, was reserved for Africa, which last year managed a two-point or 4% improvement, despite the high-profile incidents in the DRC and Tanzania," he said.

The Permitting Index is a new addition to the World Risk Report this year and, like the Opportunity Index, comes purely from responses to the World Risk Survey.

Each year Aspermont collects some 3,500 unique and aggregated data points, which Cann said deepened the value of the database with every report published.

The comprehensive annual review of mining risk and trends is now available online.