A knowledge of accounting

Totally agree with Rohan; whilst you might not be performing data entry or preparing journals or even trial balance; the ability to read and interpret financial statements is a skill contemporary managers need.

The foundations of an MBA program is based on analysis with the ability to interpret not only financial data; the ability to interpret economic data and relevant business information is critical. Whilst not every role requires operations management, marketing or finance, you had better believe analysis and accounting is the core of the decision making process.