This paper proposes and illustrates a methodology to assess the economic cost of the sovereign risk finance instruments available to the Government of Ethiopia and its development partners for financing the shock-responsive scalability component of the Productive Safety Net Programme. The methodology involves: (i) specifying rules for when additional expenditures would be triggered in each woreda; (ii) specifying alternative risk finance strategies; and (iii) analyzing the costs of each risk financing strategy, including sensitivity and scenario testing of the results. The methodology is applied to a hypothetical set of rules for drought-responsive scalability, and a range of potential risk finance strategies.