TY - GEN AB - We solve an infinite time-horizon bounded-variation stochastic control problem with regime switching between *N* states. This is motivated by the problem of a government that wants to control the country's debt-to-GDP (gross domestic product) ratio. In our formulation, the debt-to-GDP ratio evolves stochastically in continuous time, and its drift - given by the interest rate on government debt, net of the growth rate of GDP - is affected by an exogenous macroeconomic risk process modelled by a continuous-time Markov chain with *N* states. The government can act on the public debt by increasing or decreasing its level, and it aims at minimising a net expected cost functional. Without relying on a guess-and-verify approach, but performing a direct probabilistic study, we show that it is optimal to keep the debt-to-GDP ratio in an interval, whose boundaries depend on the states of the risk process. These boundaries are given through a zero-sum optimal stopping game with regime switching with *N* states and we completely characterise them as solutions to a system of nonlinear algebraic equations with constraints. To the best of our knowledge, such a result appears here for the first time. Finally, we put in practice our methodology in a case study of a Markov chain with *N* = 2 states; we provide a thorough analysis and we complement our theoretical results by a detailed numerical study on the sensitivity of the optimal debt ratio management policy with respect to the problem's parameters. DA - 2019 KW - singular stochastic control KW - zero-sum optimal stopping game KW - free-boundary problem KW - regime switching KW - debt-to-GDP ratio LA - eng PY - 2019 SN - 0931-6558 TI - Optimal Control of Debt-To-GDP Ratio in an N-State Regime Switching Economy UR - https://nbn-resolving.org/urn:nbn:de:0070-pub-29338135 Y2 - 2024-11-22T14:51:32 ER -