> If I buy a loaf of bread for $1, who gains and who loses? I lose $1 and gain a loaf of bread. The baker gains $1 and loses a load of bread.
You have failed to make reference to the key part in my two statements, profit. There is a "finite" amount of money in the economy at any given time. This is much like energy and its place within the universe. Energy and money can only move around. There is no way that everyone and every company can take profit since this would need for more money to exist than what actually exists.
As for your baker...
The baker has a true cost associated with getting that loaf to the market and through its sell that must be covered by his or her pricing. The true cost is more complex than materials and labor. He or she also likely has a desire to earn a profit. In an ideal market, the baker would sell the loaf at cost-plus-profit with the pricing in line with the customer's buying power. If his total overhead is $1, he makes no profit on a loaf sold at $1. If, on the other hand, his cost is $0.50, he's earned quite the profit.
Let's say his cost rises and/or the customer can no longer pay $1 for a loaf of bread. Let's also say he is too attached to the profit of 50 cents on the dollar he's had to-date. So, what does the baker do? He finds a way to cut his costs. Sometimes this achieved through improvements in efficiencies that that doesn't impact others. Now, I'd argue that all change has impact. He could skimp or otherwise change the recipe in such a way that lowers quality. Who loses to allow the baker to gain? The customer. Let's say he choses to cut bakery staff to reduce costs so that he can gain. Who loses? The workers and anyone dependent on the workers' income lose. The society also loses, because the workers have less or no money to spend. Society might also lose further by having to pay for social safety net services to be used by the workers until the income can be replaced. Let's say the baker raises the price of the loaf to protect his profit. Who loses here? The customer and quite possibly society again. Let's say the baker choses to not pay his suppliers, landlord, and/or for utilties to reduce his costs. Who loses? The company that has been shorted loses, and their employees might lose in time due to the company's drop in revenue.
Gains and losses aren't always measurable in currency. Lowering product and service quality to maintain or increase gain also has a corresponding loss. Examples of correlated gain and loss are available through out our economy at all levels and life in general. Some gains by one are so great that the burden of a corresponding loss is felt by many. I don't want to step on another to get ahead. A person or company that is gaining more than they are losing are stepping on someone to get ahead.