It is the purpose of sections 84-131 to 84-141 to promote the development of the state's human, economic, and physical resources; to promote the health, safety, and general welfare of its citizens; and to secure the economical and efficient expenditure of the state's revenue by creating, within the executive branch, an office for development and review of policy alternatives. The office shall act as a directing, advisory, consulting, and coordinating agency to harmonize planning and policy development activities at all levels of government within Nebraska, and to stimulate public interest and participation in the social, economic, and physical development of the state.