Yes, they do rise spontaneously.  There are <i>not</i> more people living and working in the area: the prices of the <i>existing</i> houses have risen, just because of speculation and flipping.  It&#x27;s not like there&#x27;s more people getting packed into these houses (for the most part).<p>You only get more people living and working in the area if you <i>build more houses</i>.  If you do that, then of course you&#x27;re going to have more property tax, even if the existing house values don&#x27;t change at all.  New houses = new property taxes.  That&#x27;s how you pay for the extra policing, not by soaking the existing residents.