normally, when the markets crash, do prices go up or down?
Prices of what? And are you referring to stock markets when you say “markets crash”?
lets say stocks crashing.
general prices. CPI.
I’ll hazard a guess (and this is nothing better than a guess):
I believe this is an empirical question and depends on the particulars of why the market crashed moreso than just the acknowledgement that the market crashed. In other words, each case of the market crashing could spawn different results.
If the market crashed simply because demand for stocks decreases, that could mean that demand for other goods goes up. Prices of those goods would rise. Whether those goods are measured in CPI is a different story.
If, however, the market crashed because, say, a nation-wide real estate bubble burst then prices could go down as demand for goods drops while people try to dig their way out of debt. Similarly, the market could crash because Japan is under water, in which case supply of some goods could decrease. This could cause price increases.
The very point of a market crash is that the percieved value of the product plummets. Value plummets price falls.