This compilation discusses the two latest economic crises, 2009 and 2020, and the public policies used to mitigate the recession, improve economic growth, and save people from the dangerous coronavirus. The authors summarize the principal legislation and recommendations that, from the point of view of corporate governance, have been established in the Spanish context in relation to: risk control and management, the role of audit committees in the supervision of risk control and management function and transparency in all these issues. The development levels of central and eastern European countries which transitioned from socialist economies to market economies and experienced major changes in their institutional structures are assessed. Additionally, an optimal control problem of water management is examined in the context of the conjunctive use of two interrelated water sources: groundwater and rainwater.