This doctoral thesis consists of four essays. The first chapter, titled "Scenes from a Monopoly: Quickest Detection of Ecological Regimes" studies the stochastic dynamics of a renewable resource harvested by a monopolist where harvesting affects the resource’s potential to regenerate, resulting in sequential endogenous regime shifts. The model encapsulates environmental surveillance of ecological dynamics where the firm has to find the profit-maximizing extraction policy while simultaneously detecting in the quickest time possible the change in regime. The second chapter, titled "Firm Decisions Under Jump-Diffusive Dynamics" presents a realistic model of firm investment under uncertainty and partial irreversibility in which uncertainty is represented by a jump diffusion. This allows to represent both the continuous Gaussian volatility and the discontinuous uncertainty related to information arrival, sudden changes and large shocks. The model shows how both sources of uncertainty in the market conditions impact the firm’s optimal investment and disinvestment threshold. The third essay, titled "Coronagraben. Culture and social distancing in times of COVID-19" investigates whether cultural differences, within the context of Switzerland, play a role in the heterogeneous compliance to social distancing measures during the COVID-19 pandemic. The final chapter "Superbug Stories" studies the role of intensive farming and antibiotic consumption in driving the growing crisis of antimicrobial resistance in humans.