Who’d be a PC maker? Not Dellor HP, clearly. Investors could be forgiven for thinking the market was dying based on their slumping sales. It is not, but it is changing. If the two US makers are not careful, their hoped-for graceful exit of this former cash cow could sour quickly.

Both US companies this week blamed weakening economies. Dell sniffily dismissed its sliding market share as the result of not wanting to play in aggressively competitive “l(fā)ow value” markets. But overall PC sales – desktop and laptop – have in fact been flat year-on-year, according to Gartner, leaving the biggest Asians – Lenovo, Acerand Asustek– to gain share. When Dell talked about low value, it had a point in that the wafer-thin operating margins earned by Lenovo and Acer (2 and 0.4 per cent respectively) do not match US thinking about what is a good business. HP’s 4.7 per cent – down a percentage point in the past year – looks positively plump. Small wonder both are hoping for improved markets for their high-end products. The danger is, however, that even a better economic mood does not do as much as they hope.

There are two reasons to think that a serious risk. Emerging markets, where entry-level products are more popular, are where the growth is. PC penetration in the emerging world is about a quarter, according to Bernstein, versus 90 per cent in developed countries. There is also far lower penetration in emerging market companies, at about half of PC-involved jobs against 90 per cent again in more mature markets. The other risk is that high-end customers are exactly those most likely to delay laptop replacements in favour of tablets.