Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Eric's career includes extensive work in ...

Max Weber, a German sociologist, argued that bureaucracy was the most efficient model for private businesses and public offices. His theories influenced generations of business leaders and politicians ...

Cluster headaches can last from 15 minutes to several hours at a time, and can recur daily for weeks in a row, and then go away until another “cluster” episode. Although there is no known cure for ...