worker-owners may not believe that profit maximization is the best or only goal for their co-operative or they may follow the Rochdale Principles. As another example, worker cooperatives' flattened management structure and more egalitarian ideology often give workers more options and greater freedom in resolving work-place problems. Profits (or losses) earned by the worker's cooperative are shared by worker-owners. Salaries generally have a low ratio difference which ideally should be "guided by principles of proportionality, external solidarity and internal solidarity" (such as a two to one ratio between lowest and highest earner), and often are equal for all workers. Salaries can be calculated according to skill, seniority or time worked and can be raised or lowered in good times or bad to ensure job security. Internal structure Worker cooperatives have a wide variety of internal structures. Worker control can be exercised directly or indirectly by worker-owners. If exercised indirectly, members of representative decision-making bodies (e.g. a board of directors) must be elected by the worker-owners (who in turn hire the management) and be subject to removal by the worker-owners. This is a hierarchical structure similar to that of a conventional business, with a board of directors and various grades of manager, with the difference being that the board of directors is elected. If exercised directly, all members meet regularly to make—and vote on—decisions on how the co-operative is run. Direct workers' cooperatives sometimes use consensus decision-making to make decisions. Direct worker control ensures a formally flat management structure instead of a hierarchical one. This structure is influenced by activist collectives and civic organizations, with all members allowed and expected to play a managerial role. Such structures may be associated with political aims such as anarchism, libertarian socialism, distributism, and participatory economics. Some workers' cooperatives also practice job rotation or balanced job complexes to overcome inequalities of power as well as to give workers a wider range of experiences and exposure to the different jobs in a workplace so that they are better able to make decisions about the whole workplace. The Mondragon Bookstore & Coffeehouse (now defunct) is a good example of a workplace that used this practice. Worker collectives The term 'worker collective' is sometimes used to describe worker cooperatives which are also collectives: that is, managed without hierarchies such as permanent manager roles. Common ownership is practiced by large numbers of voluntary associations and non-profit organizations as well