The first t-o summands <3> can be Interpreted as the national Income growth resulting from the expansion of volume of the production resources being used whereas the third summand reflects changes In the national Income due to better use of .the production resources In a given period of time compared to whet has been originally planned on the bats of the normative set for this Interval of time. It Is not difficult to show ~hat It Is Just so. It Is known that the national Income growth takes place under the Influence of two factors -an Increase In number of workers engaged In material production and an Increase of labour productivity. In Its turn the.growth of labour productivity results from provision of labour with better tools. utilization of advanced technologies saving not only alive but also pest labour, better organization and management of production. Let us assume that In one year the national Income has grown by6Y, where 6Y = Y-Y • If the labour productivity In year t t t-1 remained at the level of a previous year. I.e. t-1, the national Income growth resulting from the Increase ~f number of workers engaged In the material production would have been <Yt•1)/ Lt-1 .... Lt where Y /L stands for t-1 t-1 labour productivity In the previous year and.Lt denotes the Increment of workers engaged In· the materiel production during year t In relation to year t-1. However, the basis of labour productivity and ensuing growth of the national Income have been determined by keep lng capital/labour ratio unchanged. This requires additional l nvestment In amount of6F• = Ft-1/Lt.i~L In thIs case.F· value Is a sort of compensator of the unchanged labour productivity. In view of this It Is rightful to state that a part of the national 
**Analysis**
The text appears to be discussing the growth of national income, labor productivity, and the use of resources in a given period of time. It mentions the expansion of production resources, changes in the use of resources, and the impact of labor productivity on national income growth. The text also mentions the concept of a "compensator" to maintain a constant labor-capital ratio. Based on this content, it seems likely that the text is related to economic development and employment.

**Category**
Economic development, Employment