The Master of Business Administration (MBA or M.B.A.) degree originated in the United States in the early 20th century when the country industrialized and companies sought scientific management. The core courses in an MBA program cover various areas of business administration such as accounting, applied statistics, business communication, business ethics, business law, business strategy, finance, managerial economics, management, entrepreneurship, marketing, supply-chain management, and operations management in a manner most relevant to management analysis and strategy. Most programs also include elective courses and concentrations for further study in a particular area, for example accounting, finance, and marketing. MBA programs in the United States typically require completing about forty to sixty credits (sixty to ninety in a quarter system), much higher than the thirty credits (thirty-six to forty-five in a quarter system) typically required for degrees that cover some of the same material such as the Master of Economics, Master of Finance, Master of Accountancy, Master of Science in Marketing and Master of Science in Management. The MBA is a terminal degree and a professional degree. Accreditation bodies specifically for MBA programs ensure consistency and quality of education. Business schools in many countries offer programs tailored to full-time, part-time, executive (abridged coursework typically occurring on nights or weekends) and distance learning students, many with specialized concentrations.