As is the case with conventional job subsidies, STW schemes confront a trade-off between cost-effectiveness, on the one hand, and scale on the other (Martin and Grubb, 2001). For example, tight eligibility requirements and relatively low subsidies can reduce deadweight and displacement effects, but are also likely to discourage take-up by some firms where it would be socially efficient. Annex 1.A1 presents an overview of the main features of these STW schemes in 22 OECD countries, organised around work-sharing requirements, eligibility requirements, conditionality requirements and generosity.