if you spend more than you make that year, then it reduces what you have to pay in taxes. people with savings that far exceed what they earn that year, that they actually spend towards something revenue producing, will not pay taxes on what they earn. if you have outside capital that you spend, and that exceeds your earnings that year, then you have no tax to pay. smaller participants can operate this way too. if they don't have capital and are barely making ends meet by spending what they earn on consumptive things (even if necessary) then they have taxes on what they earn. this is the same for larger organizations if they chose to operate that way. not everyone has access to capital, or savings, or willingness or the risk profile to use their savings towards additional growth. but if you do take the risk, then thats the reward.