If your expenditure brings you poverty, then you may call yourself a poor but the world will call you a fool.
My simple explanation of why we human beings, the most advanced species on earth, cannot find happiness, is this: as we evolve up the ladder of being, we find three things: the first, that the tension between the range of opposites in our lives and society widens dramatically and often painfully as we evolve; the second, that the better informed and more intelligent we are, the more humble we have to become about our ability to live meaningful lives and to change anything, even ourselves; and consequently, thirdly, that the cost of gaining the simplicity the other side of complexity can rise very steeply if we do not align ourselves and our lives well.
Jean-Baptiste Say may have coined the term 'entrepreneur' but he totally missed the opportunity to put it on a t-shirt and sell it.
When an economist attempts to prove that it is "irrational" to vote in national elections (because the effort expended outweighs the likely benefit to the individual voter), they use the term because they do not wish to say "irrational for actors for whom civic participation, political ideals, of the common good are not values in themselves, but who view public affairs only in terms of personal advantage.
Have you heard the joke about the chemist, physicist and economist who get wrecked on a desert isle, with a huge supply of canned baked beans as their only food? The chemist says that he can start a fire using the neighbouring palm trees, and calculate the temperature at which a can will explode. The physicist says that she can work out the trajectory of each of the baked beans, so that they can be collected and eaten. The economist says "Hang on guys, you're doing it the hard way. Let's assume we have a can opener.
Invitation is not only a step in bringing people together, it is also a fundamental way of being in a community. It manifests the willingness to live in a collaborative way. This means that a future can be created without having to force or sell it or barter for it. When we believe that barter or subtle coercion is necessary, we are operating out of a context of scarcity and self-interest, the core currencies of the economist.