In response to the post about Modern Times not being allowed to renew their Valencia St. lease so the landlord could (presumably) find a higher-paying tenant, reader Jermey brought up the idea that we tax landlords who leave storefronts empty:

Does anyone know if the landlord has a new tenant lined up, or is it going to join the ranks of the empty storefronts on Valencia while the landlords hold out and wait for someone willing to pay outrageous rent?

I hope the Supervisors follow up on the City economist's suggestion to create a tax on vacant commercial properties to encourage landlords to lower the rents to where businesses that don't sell $100 meals or $500 jeans can afford to pay them.

Not a bad suggestion.  As anyone who has actually studied economics and isn't in the Tea Party can tell you, communities often levy a tax on negative externalities (e.g. we tax the sale of gasoline because it pollutes our air).  Since empty storefronts have a negative effect on SF (blight, reduced commerce, harder to start a small business), it would seem reasonable to enact a tax that discourages landlords to leave units empty and evict small businesses in favor of finding a higher-paying corporation to fill the space.  Then again, this would be blasted as anti-business by the developers of the city, so there will doubtfully be any political capital to make it happen.  Nice to dream though?