Deflation is "unfair" too.
-person Y starts a business paying their workers fro 40 hours a week.
-person Y make a building and will use their gains for housing himself and his family with this amount.
...
Deflation occurs and he has not gained enough to cover housing and food for him and his family. Maybe he can't even pay the loan ha asked for starting the business.
This is my first post, and I'd like to take a stab at this. There really isn't enough information to go on, but let me try by filling in additional information:
Person Y makes a carrot picking machine. The resources that go into the carrot picking machine cost 2ⓑ and the labor is also 2ⓑ. The machine is sold for 5ⓑ.
Deflation occurs...let's say 10% so it's a bit easier to do the numbers with. The carrot machine now has to cost 4.50ⓑ to keep in line with what Person Y's competitors are pricing it at.
If deflation is occurring, then it effects all prices, so the resources to make the machine have also deflated in price 10%, or instead of costing 2ⓑ, they cost 1.80ⓑ.
Additionally, in an economy where deflation is occurring the employer has a couple choices when it comes to how the employees are paid. If paying employees hourly, then most likely instead of employees getting pay raises they would get a decreasing pay scale normally and a flatter pay scale if a great worker. Another possibility is that employees are paid per machine, and so when the deflation occurs the employer adjusts the amount per machine down directly.
Either way reduces the amount for labor to 1.80ⓑ instead of the previous amount. This is an additional cost reduction of 0.20ⓑ.
Adding up the costs now gives a total amount of: 3.60ⓑ with a profit of 0.90ⓑ which matches the deflation.
What is the end result of the deflation? All goods and service costs are reduced 10% so Person Y is still able to pay for their home and family.
This hypothesis assumes that deflation immediately and everywhere, which doesn't accurately reflect reality, but I don't think a double digit deflation would reflect reality either. It is important to understand that every Person Y is someone else's Person X, so while short term losses could happen for a Person Y, they are likely to be offset rather quickly.
As far as a home loan would be concerned, I think in a deflationary society the "loan" would just require the principal to be repaid instead of the current requirement of interest that exceeds the inflation of the money supply. The person taking out the loan would strive to pay off the loan as quickly as possible, so that they can hold on to more of their money's value. The person who loaned the money would be fine to wait until the full payment schedule is completed, so that they would have the added value the deflation added to the purchasing power of the money.
That I think may be the hardest thing for me to wrap my head around. While it's easy to see that something that cost 1ⓑ now costs 0.90ⓑ means that the item now is 90% of it's cost, what happened to a person's purchasing power? If a 1ⓑ purchase in the past now only takes 0.90ⓑ, the value of a bitcoin has increased. If my math is correct, the increase is 11%. This means that a person actually gains additional value from deflation for their existing funds.