(This guest post originally appeared on the author's blog)

Back in 2005, I did a fun exercise for New York Magazine - I was asked to value Central Park (just for fun) in about 3 minutes. It was within an article that ranked the reasons to love New York and was item number 3.

The New York Observer recently asked me to update this calculation using the same methodology (in 3 minutes and just for fun) and I came up with $363,538,692,000 which is a far cry from $528,783,552,000. The same disclaimers apply as the original effort, seriously.

To put this in perspective, about 9,000 Detroit properties were auctioned (hat tip WalletPop) with opening bids of $500. Only 20% received bids. The total land area of these properties was equivalent to Central Park. If all 9,000 properties received a bid of $500 (which is probably not far off if you assume the 20% that received bids were over $500 and the rest $0), that represents a total value of $4,500,000.

Thats’s not much of a value and these properties also pull down values around them - plus they are off the tax roll placing more financial burden on existing properties.

Not a good sign

Most of the bidders were investors and vacant land in Detroit equals the entire footprint of Boston.

As much as I love my time spent in Michigan and my relatives there, I believe this is called an economic failure spiral.