Agglomeration

There's a fascinating article in The Daily Mail about a massive open market in Ukraine somewhere which consists of thousands of old shipping containers which were bought for a song. There appears to be electricity laid on, the containers are laid out in neat rows ("streets"), there are bus services from the nearest towns... and that's about it.  The rents the traders pay seem to be sky-high, but what are they paying for? They are paying for the passing trade, the 150,000 people who turn up every day looking to buy (or sell) stuff. And what attracts those people? All the other traders.  So each trader is contributing in some small way towards making this an attractive place to go shopping (benefitting the other traders) and is equally benefitting from the presence of all the other traders. Overall, there is a gain to be made by trading from there - you lose a few roubles to your competitors but gain many more by being near them. This is "agglomeration" in its purest form.  So what moral justification is there for the traders between them to be paying a million dollars every month to somebody who basically owns a few big fields? Apparently government tax collectors and inspectors are unwelcome there, which makes the place even more attractive, but if the Ukraine government wants to collect tax from the market, the easiest thing to do is just take it from the land owner who appears to do little but collect the rents.  If he refuses to cough up, the government can just set up its own market a few miles down the road, shut down the existing one and change the bus routes. The government then declares the new market to be a "tax free zone" and charges rents (the least-bad form of taxation) accordingly.  From the look of it, it won't be too difficult to make the new market more attractive than the old one (wider "streets", public toilets, better layout, chuck in a kids' playground or something etc).