Worldwide PC shipments are expected to fall -10.0% in the fourth quarter of 2015, pulling year-over-year growth for all of 2015 down to -10.3%, according to the International Data Corporation (IDC.) Short-term headwinds like the strong dollar, depressed commodity prices, and existing inventory have also lowered the outlook for early 2016, although shipments are still expected to stabilize by the end of 2016 and grow slightly toward the end of the forecast as commercial replacements rise.

IDC estimates that disruptions from political and economic transitions will have a particularly large impact on Japan, the Middle East and Africa (MEA), Central and Eastern Europe (CEE), and Latin America. Japan and MEA in particular will experience double-digit lower growth over the next year or more, while the CEE and Latin America regions have a short-term outlook that is in the high-single-digits lower. In contrast, the forecast for the United States, Western Europe, and Asia/Pacific (excluding Japan) will be only slightly lower, and Canada improved slightly.

Beyond short-term declines, IDC remains optimistic that replacements of commercial and consumer systems will ultimately stabilize the market and even drive growth. Once commercial adoption of Windows 10 accelerates, and in combination with upgrades to steadily aging consumer PCs, IDC expects demand for new PCs to improve for several years as replacements will also be boosted by the end of support for Window 7, just as the end of support for Windows XP boosted shipments in 2014. Declining tablet volume, and minimal growth in mobile phones (despite the continuing shift to smartphones) will also reduce pressure for consumers to spend on non-PC devices.

While detachable tablets are expected to grow quickly, they are still a relatively small part of the market. As a reference, combining detachable tablets with PCs would boost growth by roughly 3 percentage points ? this would result in a trend of declining volume from 2012 to 2015, followed by about 1% growth in 2016 and slightly higher gains in subsequent years.

In the United States, the consumer PC segment will continue to erode. Smartphones and tablets have increasingly eaten into the consumer share of wallet and kept PC purchases at the back of the refresh queue. Growth of the detachable tablet category will only further slow consumer PC shipments as some consumers elect to replace their existing PCs with the new form factors.

IDC believes that the declines in the U.S. consumer PC segment will be somewhat offset by growth of commercial PC shipments through the forecast period. "Beyond a slow but steady churn in the installed base, Windows 10 could reach enterprises faster than previous releases driving some commercial PC refreshes in the mid-term," said Linn Huang , Research Director, Devices & Displays. "Additionally, the U.S. K-12 market continues to gain momentum as vendors increasingly focus their Chromebook strategies there."

PC Shipments by Product Category and Region (Shipments in millions)

Source: IDC Worldwide Quarter PC Tracker, December 4, 2015

* Forecast data