Book excerpt: Most research about financial stability and sustainable growth focuses on the financial sector and macroeconomics and neglects the real sector, microeconomics and psychology issues. Real-sector and financial-sectors linkages are increasing and are a foundation of economic/social/environmental/urban sustainability, given financial crises, noise, internet, “transition economics”, disintermediation, demographics and inequality around the world. Within complex systems theory framework, this book analyses some multi-sided mechanisms and risk-perception that can have symbiotic relationships with financial stability, systemic risk and/or sustainable growth. Within the context of Regret Minimization, MN-Transferable Utility and WTAL, new theories-of-the-firm are developed that consider sustainable growth, price stability, globalization, financial stability and birth-to-death evolutions of firms. This book introduces new behaviour theories pertaining to real estate and intangibles, which can affect the evolutions of risk-taking and risk perception within organizations and investment entities. The chapters address elements of the dilemma of often divergent risk perceptions of, and risk-taking by corporate executives, regulators and investment managers.