"The connectedness of New Zealand society means that a large percentage of Kiwis will be hearing bitter complaints about these two groups from disgruntled Christchurch family and friends."
Naylor said international research showed the impact on American general insurance companies who had poor responses to natural disasters could be substantial and long-lasting.
But Vero New Zealand spokesman Ron Burke said the American insurance industry was different to New Zealand and Australia and in his experience the market share of New Zealand and Australian companies had remained steady despite concerns about pace and quality of insurer responses to previous disasters.
"Australia's insurers have managed five major disasters during the past six years including floods, cyclones, storms and bushfires," Burke said.
"The recovery from all of these has started with considerable customer, government and community concern about the pace and quality of insurer responses," he said.
"That has always decreased as the recovery programmes proceed and claims are finalised."
Burke said the share price of Suncorp, Vero's parent company, had outperformed the ASX 200 index despite five years of disaster recoveries.
A spokesman for the New Zealand arm of IAG said there had been no significant change to its market share in New Zealand since the Canterbury earthquakes began in September 2010 aside from an increase attached to its acquisition of AMI.
Before acquiring AMI it had around one third of the market share and that had increased to 40 per cent after buying AMI.
The spokesman said all parties involved in the Canterbury recovery efforts faced challenges that have reputational risk attached.
"We take nothing for granted," he said.
"Our commitment is for the long-term and our scale and strength we know is important for people with or seeking insurance.
"We believe this is recognised by many of our customers now and will continue to be recognised over time."
IAG's share price had risen by around 25 per cent since the beginning of 2012, he added.
Insurance Brokers' Association of New Zealand chief executive Gary Young said he doubted the Canterbury situation would have an impact on the market share of the insurance companies.
"People's memories are short," he said.
Young said all of the companies would have learned a lot from the quakes and how to respond in the future which was likely to result in a change to policies.'
BANKS IN LINE FOR FALLOUT
Massey University insurance professor Michael Naylor believes any negative impact on the reputations of the insurance companies will have repercussions for the insurance brokers and banks which recommend them.
"The problem for banks is that, while they make profits selling insurance, they do not decide on claims, but their reputations are tarnished when the policies are poorly serviced."
Naylor said the fallout could force brokers and banks to switch whom they recommended to their customers.
But Gary Young, chief executive of the Insurance Brokers Association of New Zealand, which has 150 corporate members covering 2000 brokers, doubted many brokers would change their recommendations.
"Some of them might like to switch. But the problem we have got is that no one will take on new business."
In the case of reinsurance for some properties, brokers were having to find more than one insurance company to take on the risk, he said.
"Now is not the time to [switch]. They have to wait for a year for the capacity issues to be sorted out."