system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 - Why is it bad for money to have a fixed value over time?

What's the harm in a dollar's worth being constant? Why is an inflation rate of zero bad?
gpt
Having inflation increases investment, it makes it disadvantageous for you to have  tons of cash just laying around. In fact a big problem now is that companies and people are hoarding cash, with inflation there's a big push to invest in things such as an expansion or hiring new employees, because you effectively lose money if you do nothing with it. 

0% inflation isn't necessarily bad, its just not optimal, but negative inflation is terrible and was one of the biggest issues in the Depression. Farmers were burning their crops because the prices were so low it wasn't even worth selling them, while people in the cities starved. You can see something similar today with the housing market, where no one wants to buy because the prices keep falling.