That would be the most naive interpretation of the relationship - what if, for example, the invisible homeless also burden charities and other support systems in a way that leads to more visible homelessness? What if, given that high prices are a sign of lack of supply, visible homelessness is just a symptom of lack of construction in the county?

"Suppose the house price drops" is a very non-specific hypothetical. Why would the house price drop, and what impact could that have on homelessness?