The old saying, "a penny saved is a penny earned" is only half the story. For sure that penny you didn't spend is still in your pocket but it also hasn't gone whirling through the 'economy' either. With each whirl a bite gets for taken out for somebody's profits, interest and taxes. It's the Toilet Bowl theory of economics. Just like how gravity pulls at the water going around in the toilet so that quickly all the water is down the drain, so to do profits, interest and taxes pull the buying power of your penny down the drain after a few revolutions.
In Money and Banking class, about a million years ago, i learned that velocity matters far more than volume in matters financial. Every time the economy turns over the billionaires, bankers, government get a their bite. The faster the action, regardless of the size, the better. The demands of velocity are relentless, the mortage works night and day, Sundays and holidays always moving, always multiplying even when we sleep.
Just as a penny saved is a penny denied the draw of the drain so to is money not spent on most stuff. Money not spent is profits ungouged, interest unaccrued and taxes uncollected. Money unspent retains its potential energy in your pocket and still creates a effect by denying the drain the kinetic energy it would have otherwise had. So too for the stuff your penny didn't buy, it too didn't consume the embedded bite of the drain at each exchange on its journey to your house.
Imagine a corrot, two carrots really. One carrot you grow in a patch out back, the other grows in some agro-industrial complex somewhere. Your backyard carrot grew from a tiny seed, was fed by the sun, the microbes in the soil and your watering. It arrived in your kitchen, as the Japanese say, "right on time", its quality is beyond comparison with its agrobusiness lookalike, it has an almost zero embedded carbon footprint, it has in fact sequestered atmospheric carbon to grow itself [its orangy goodness the product of Gaia's alchemy], its remains return to the compost as food for the microrganisms whose poop will feed next season's bounty. One little carrot can make a triple difference, #1 the penny you still have, #2 the penny denied to the drain and #3 the embedded costs to the enviroment uncharged by the unbought agro-carrot.
We can change the world one carrot at a time if need be. Victory Through Vegetables!