Consumers’ growing appetite for tablets is eroding demand for personal computers, according to a new report from International Data Corporation (IDC).

Global PC shipments declined 3.2 percent in the first quarter of this year compared to the same period last year, missing the research firm’s previous forecast of a 1.5 percent growth in shipments.

IDC attributed the slump to consumer complacence with the “good enough” computing power in tablets, whose size, content and user interface offer a more compelling experience to consumers than PCs. Consumers are holding off on upgrading their computers as they flock toward new tablets like Apple’s iPad.

Wider economic conditions, including a spike in fuel and commodity prices and the earthquake in Japan, have added to the decline in shipments.

“While it’s tempting to blame the decline completely on the growth of media tablets, we believe other factors, including extended PC lifetimes and the lack of compelling new PC experiences, played equally significant roles,” IDC researcher Bob O’Donnell said the report.

O’Donnell said the slump in PC shipments will continue into the second quarter, but will start to improve in the second half of this year.

On a regional basis, PC shipments in the United States fell more than 10 percent in the first quarter compared to last year. Shipments increased 5.6 percent in the Asia Pacific region, but were partially offset by a nearly 16 percent drop in Japan, which is still struggling to recover from last month’s devastating earthquake.

IDC analyst Jay Chou said PC vendors must make major changes to their products to regain the attention of consumers distracted by the allure of tablets.

“Macro-economic forces can explain some of the ebb and flow of the PC business, but the real question PC vendors have to think hard about is how to enable a compelling user experience that can justify spending on the added horsepower,” Chou said.