Can large-scale technology raise small-miner income and reduce mercury? Prospects for female waste-rock collectors selling ore to non-mercury processing plants

Artisanal-and-small-scale gold mining supports millions of livelihoods in the Global South but is the largest anthropogenic source of mercury emissions. Many initiatives promote mercury-free technologies that small miners could employ. Few document mercury impacts. We study an alternative: instead of processing themselves, small miners sell their ore to plants employing larger-scale, mercury-free technologies that also raise gold yields. Some ore-selling occurs without policy intervention, yet impacts on incomes and mercury use remain unclear. We assess ore-selling preferences of female waste-rock collectors (jancheras) in Ecuador, using a discrete-choice experiment. Results demonstrate that jancheras generally are open to ore-selling, yet often reject options similar to a recent pilot intervention. Offers that address formalization hurdles (invoicing), inabilities to meet quantity minima (given limits upon association, storage, and credit), and constraints on trust (including in plants’ ore testing) could increase adoption by tailoring related interventions to the preferences of and challenges for defined populations.