A hybrid standard macro model is supplemented by an explicit analysis of bank lending, based on a five-position aggregative balance sheet. In the model's two versions credit supply is based on a leverage targeting rule or on simple optimisation, taking into account lending risks and funding costs. Model simulations explore consequences of supply and demand disturbances, discretionary interest rate moves, asset valuation and credit risk shocks. Besides standard Taylor policies, the paper compares the relative efficiency of additional stabilisation tools like external-funding taxes and anti-cyclical leverage regulation. Quantitative restrictions for bank activities seem to be useful.