Table:
| Year Ended May 31, |  |  |  |  |
| --- | --- | --- | --- | --- |
|  |  |  | Percent Change |  |
| (Dollars in millions) | 2019 | Actual | Constant | 2018 |
| Research and development (1) | $5,063 | -2% | 0% | $5,163 |
| Stock-based compensation | 963 | 5% | 5% | 921 |
| Total expenses | $6,026 | -1% | 0% | $6,084 |
| % of Total Revenues | 15% |  |  | 15% |
Paragraphs:
Research and Development Expenses: research and development expenses consist primarily of personnel related expenditures. We intend to continue to invest significantly in our research and development efforts because, in our judgment, they are essential to maintaining our competitive position.
(1) Excluding stock-based compensation
On a constant currency basis, total research and development expenses were flat in fiscal 2019, as lower employee related expenses including lower variable compensation were offset by an increase in stock-based compensation expenses .
Question:
What is the primary component of Research and development expenses?
Answer: Research and development expenses consist primarily of personnel related expenditures.