Starting in 1918 at General Motors I found to my surprise] that if I followed the prevailing practice of intercorporate relations I would no longer be able to determine the rate of return on investment for these accessory divisions individually or as a group. This would necessarily mean that I would lose some degree of managerial control over my area of operations. At that time, material within General Motors was passing from one operating division to another at cost, or at cost plus some predetermined percentage. My divisions in the United Motors Corporation had sold both to outside customers and to their allied divisions at the market price. I knew that I operated a profit-making group, and I wished to continue to be able to demonstrate this performance to the general management, rather than to have my operating results on interdivisional business swallowed up in the extra bookkeeping profits of some other division. It was a case of keeping the information clear.