People who make less than $50,000 a year, are divorced or don’t bundle their auto and homeowners insurance coverage are most apt to switch insurance carriers, new research suggests.

In the past 12 months, 30% of households with annual incomes below $50,000 shopped for a new insurance carrier and 45% of those customers eventually switched carriers, according to the J.D. Power and Associates 2009 Personal Insurance Retention Special Report.

In contrast, only 26% of more affluent households (those with incomes of $100,000 or more) shopped for a new carrier, with only 31% of shoppers eventually switching.

About 90% of customers overall stayed with their insurance carrier during the past 12 months, “households that are potentially more impacted by the recession present a real challenge for insurance carriers,” said Jeremy Bowler, senior director of the insurance practice at J.D. Power and Associates, in a statement.

He said several carriers, including Auto-Owners, GEICO, Liberty Mutual, Progressive and Travelers, have increased their customer base in this challenging economic climate, their growth comes at the expense of other insurers in the mature U.S. personal auto insurance market.

“As such, keeping customers on board is absolutely critical for the long-term profitability of an insurance carrier,” Bowler said.

Retention rates are particularly high among those customers who bundle multiple insurance products, according to the report. Retention rates average 95% among customers who bundle home and auto policies with the same insurance carrier and 92% among those who bundle auto and rental policies. Conversely, retention averages only 83% among mono-line auto customers and only 85% among policyholders who do not bundle their auto and homeowners insurance.

“For any of the 50 largest U.S. personal auto insurers, improving retention by one percent for the next five years can equate to tens of millions of dollars over that time period, so even seemingly small differences in retention rates can have a substantial impact on an insurance company’s bottom line,” said Bowler. “Making strides to improve satisfaction and retain customers clearly has a significant financial incentive for carriers.”

The report also finds that there are considerable variances in customer retention between different consumer demographic or attitudinal groups.  For example, while retention rates average 91% among married customers, the retention rate among divorced policyholders is 5 percentage points lower, on average.

“In light of differences between demographic groups, which can be indicative of different lifestyle and insurance needs, auto insurers need to tailor their products, services and retention tactics to specific attitudinal or demographic segments to increase the likelihood of retaining customers, rather than treating everyone with a ‘one size fits all’ mentality,” said Bowler.

The 2009 Personal Insurance Retention Special Report is based on surveys from more than 275,000 auto insurance customers evaluating more than 30 insurance carriers across the industry, including AIG /21st Century, Allstate, American Family, Farmers, GEICO, Liberty Mutual, Nationwide, Progressive, State Farm, The Hartford, Travelers and USAA. The study was performed from January to March.