From the note:
What is a Development Impact Bond?
Development Impact Bonds (DIBs) bring together private investors, non-profit and private sector service delivery organisations, governments and donors to deliver results which society values. They are a family of outcomes-based contracts in which private investors pay in advance for interventions needed
to achieve agreed results, and work with delivery organisations to ensure that the results are achieved; donors and/orgovernments make payments to investors if the interventions succeed, with returns linked to progress achieved. If the interventions fail, investors lose some or all of their investment.