New research suggests that Target's massive data breach is affecting customer satisfaction levels.

Compared to last year, customer satisfaction levels dropped about three percentage points overall in customer service and about nine percentage points among upper-income shoppers, according to MarketWatch.

The finance group Cowen & Co. surveyed 2,500 shoppers in March and found “meaningful decreases” in year-over-year customer satisfaction. Its annual research aims to determine the best investment bets.

Although the data breach contributed to some of the dissatisfaction, Target's efforts to control expenses and as well as drops in traffic and sales also could also be factors.

Standard & Poor's reduced the company's credit rating last week, as well, in reaction to the breach.