Well in fairness, tax bills are based on market values, and ought to respond to events in the market. In competitive markets with lots of supply and demand, yo

Well in fairness, tax bills are based on market values, and ought to respond to events in the market. In competitive markets with lots of supply and demand, you'd expect many transactions, and the effect of any one comparable transaction on the price of a given property would be quite small. In niche markets where transactions are rare (like, say, “commercial properties in mid to lower Manhattan with >2.5mm sq ft of floor space”), individual transactions involving comparable properties can be expected to have an outsized effect.