This book contains parts of research from doctoral theses from the postgraduate program in Accounting at the University of Brasília (UnB) and from the postgraduate program in Business Economics at the Catholic University of Brasília (UCB). One research shows robust evidence that a firm or economic organization is operationally efficient if the firm or economic organization operates at full use of its installed capacity, signaled by the quantum of the Degree of Operational
Leverage (DOL) in the vicinity of 2. The other research strongly indicates that a firm or economic organization is financially efficient and operates at a sustainable level of liquidity if the quantum of the Financial Efficiency Ratio (FER) is in the range between zero and 1 (0, 1] and if the quantum of the Sustainable Liquidity Ratio (LSR) is greater than 1 and greater than the quantum of the Current Liquidity Ratio (CR), ie (1