Three theorems about choosing better of two investment schemes with the same enterprise planning horizon and the volume of investment are obtained for accelerator model. The theorems allow, without solving the differential equation, since only two investment schemes to choose one that will give a greater volume of production. All investment schemes that have the same volume of investment and planning horizon U, and symmetric with respect to a straight line, give the same amount of products released for the time period [0, T], is proved in the first theorem. In the second theorem shows that decreasing investment schedule better than growing, and the third — that since only two investment increase investment schemes is the better scheme, which have derivative. Illustrative examples are also given.