Isn't all that based on the assumption that "growth rate of the economy" is some natural process - like the universe expansion or radioactive decay - that happens regardless of what people do? It appears to me that this growth is rather the result of the effort of "self made" (to the amount of their achievement - some more, some less) people that cause it to happen, one way or another. And excluding it seems kinda wrong to me. Of course, sometimes the effort belongs to one person - e.g. the startup owner - but the benefits are shared with others - e.g. investors - and their function can be treated differently. But it's not what's happening here - here the whole investment capital is excluded altogether. I am not sure it's such a useful lens.