Tax Assessments

I noticed something when I took a look at the DC Real Estate Tax Assessment database. It is pretty much a given that the city will assess properties to be worth more than they were last year, so that, I expected. Yet when I took a look at the “Preliminary Assessment Roll” which breaks down the property values into land, improvements, and the total value I noticed a big change from the current value and the proposed value. DC has decided to pump up the land value.

Sample Assessment:

What is assessed Current Value Proposed New Value (2007)
Land $88,150 $259,920
Improvements $105,910 $122,200
Total Value $194,060 $382,120
Taxable Assessment: $194,060 $382,120

The above table I swiped from the database to show how the land value was increased. So the 2007 assessment will make the fact that one house is a rehabbed jewel and the crack house next door irrelevant because the land (provided they are similar plots) is worth the same.
Discuss.