“…A number of authors have succeeded in extending the classical results to the spectrally negative Lévy model by way of scale functions. We refer the reader to [5,6] for stochastic games, [4,7,8,25,33] for the optimal dividend problem, [1,3] for American and Russian options, and [15,17,27,32] for credit risk. In particular, Egami and Yamazaki [18] considered a general optimal stopping problem for spectrally negative Lévy processes and obtained the first-order condition for maximization over threshold strategies; the results are also confirmed numerically by [40] in a multiple stopping setting.…”