It appears that consumers have had enough with the low interest rates paid by banks. Bank deposits are shrinking for the first time in two decades, a new analysis shows.

Market Rates Insight, a San Anselmo, Calif.-based tracker of pricing data for the financial services industry, said in the first half of 2010, deposit balances in U.S. bank branches fell by $29 billion or 0.4 percent.

For nearly two decades, deposit balances withstood fluctuation in deposit rates by growing steadily.

The first half of 2010 marks the first time deposit balances are showing sensitivity to the drop in deposits rates.

The national average rate for deposits fell from 1.2 percent to 0.99 percent in the first half of 2010 – a drop of 21 basis points; 100 basis points equal one percentage.

“For nearly two decades, deposit balances as a whole were very inelastic, and kept on growing despite substantial fluctuation in the average rate paid on deposits,” said Dan Geller, executive vice president of Market Rates Insight. “It looks like in 2010 the inelasticity reached it limit.”

byerak@tribune.com