Much of modern commerce is about scale and the supposed economies that brings. Products are mass produced or, at least, collected en masse at limited numbers of sites for widespread distribution. The same type of process applies to services as centralisation gathers pace throughout the world.
The trend first began with the earliest improvements to transport and communication links, as specialisations increased and as populations grew. Just how far it has developed was illustrated by issues and questions arising from the Canterbury earthquake.
Much of the centralisation was well known, while other aspects have surprised.
Sometimes centralisation took place in two stages. Emergency fire calls from Southland as well as Otago were first centred on Dunedin. A few years later, Christchurch covered all the South Island.
Dunedin fought to retain fire, ambulance and police control centres in the South, but that battle has been lost.
Many might also have been aware that almost all Dunedin's retail milk and most of its bread now comes from Christchurch.
That city's comprehensive role as the distribution centre for supermarkets, however, was greater than widely realised. More surprising still was news that Dunedin restaurants could run low on certain Central Otago wines because of the Canterbury earthquake.
Supplies travelled to Christchurch for subsequent redistribution, and the quake laid to waste much of the stored stock. It is disconcerting, as well, to think that Central Otago apples in supermarkets are quite likely to have travelled north before being transported to Dunedin.
Such is today's world that letters going to neighbouring streets in Invercargill or Queenstown will travel to Dunedin - as one of the two South Island hubs - to be sorted before returning to the town of origin.
Does all that matter? The earthquake caused minor public inconvenience for bread and other items after distribution centres were rocked and nearly wrecked.
But milk treatment and packaging was unaffected, electricity was back on in most of Christchurch relatively quickly, most main roads remained open and commerce flowed.
Supermarkets were able to source from Wellington and Auckland, and the risks revealed by the earthquake did not escalate. It would not have taken much more, however, for major disruption.
Interestingly, the large Kaikoura slip, which this week closed road and rail links, and the floods which earlier this year cut State Highway 1 near Oamaru, raise alarm and show up vulnerability.
Christchurch Airport, although escaping with minimal tarmac damage, could easily have been devastated, and the harm to Lyttelton shows the wisdom of retaining two strong southern ports.
Naturally, post-earthquake thoughts turned to the possibility of serious damage to Christchurch hospitals and the consequences of widespread casualties.
One of the string of strong reasons for retaining resident neurosurgical capacity in Dunedin was manifest.
All these precious eggs should not be in one basket.
Of course, the centralisation and accumulation of sourcing and distribution only begins with Christchurch.
It spreads to Auckland and Australia, from where so much of our tinned and packaged food now comes, and across the world.
Sandwiches at an Ashburton petrol station have been made in Auckland.
Cadbury cream eggs now come from England, and supermarket potatoes are much more likely to have come - through distribution centres - from Pukekohe than direct from Stirling.
Who knows where many of the flour and other wheat products go to and come from?What, then, will happen in a global or local natural disaster of enormous scale? Not only would economies be shattered, but the present means of food supply and distribution could be badly exposed.
Commerce has become so dependent on specialisation and centralisation that, at the end of the food chain, the South may struggle for many basics despite its farming base.
There might be plenty of winter swedes but little bread and all sorts of other supplies.
It would seem, then, an opportune time for appropriate contingency plans to be made: it may well be that complete centralisation of services is not the answer many believe it to be.
