Congestion fees are working, or not, maybe.

Congestion fees in London are reducing congestion, and radically reshaping how Londoners use both cars and public transport. This we know. The other effects of charging are, to put it mildly, less well understood and if we are honest they are also largely unexamined.

In particular, we know very little about how charging affects retailers. Charging does have some significant positives for retailers - in particular it is very good for their logistics systems. The negative impacts are, however, very poorly understood.

While retailers [particularly John Lewis] argue that the charge is behind a drop in sales, we know that consumption patterns in the UK are still rather fluid and that:

1. mobile customers are still migrating away from inner city retailing to out of town shopping centres
2. direct retail competition to central London is growing, particularly in other city centres [especially in Birmingham, Manchester and Glasgow
3. online shopping is still growing fast in the UK: this is money that isn't going directly into high-street stores

So, how much of the retail decline in central London is the fault of the congestion charge and how much attributable to wider patterns of retail restructuring...?