Before revision:  One is to allow this hiring/firing propensity to depend on the financial fragility of firms .
After revision:  One is to introduce a bankruptcy threshold, limiting the leverage of firms. This leads to a rich phase diagram with, in particular, a region where acute endogenous crises occur, during which the unemployment rate shoots up before the economy can recover. We allow the hiring/firing propensity to depend on the financial fragility of firms .