Online shopping may not be the only culprit for the retail market's problems, says Shayla Walmsley.

That so many things can be happening to European retail markets at the same time suggests that online shopping – identified by AXA Real Estate for the demise of bricks and mortar – may not be the only culprit. In a report published this week, the fund manager claimed online shopping represents "a substantial threat" to retail assets, bringing rental values in some cases to zero as retailers struggle to meet occupancy costs.

But a couple of assumptions are open to question. One is that online retail necessarily represents a loss of trade. A second report, commissioned by UK retail property firm Hammerson, suggests instead that, by 2014, 69% of consumers will use three or more retail channels. It seems 'multi-channel strategy' is more than a marketing buzzword.

The relationship between online retail and bricks and mortar is not a binary one, where real stores suffer as their virtual counterparts thrive. Domenica Scordo, a retail analyst at BNP Paribas Real Estate, points out that, in theory, retailers losing store sales on the balance sheet are likely to attribute sales generated online to specific stores on the assumption that consumers will visit physical stores before buying online.

The implication for UK stores, according to Hammerson, is that there will be 10.3% fewer of them by 2020, but those that remain – largely in regionally dominant out-of-town centres – will be more important, not just as showrooms for subsequent online sales but as leisure hubs for "considered consumers". (Investors get it. Norges, for example, cited Meadowhall's size and dominance when it acquired the shopping centre near Sheffield for €431m last October.)

A second assumption is that consumer spending is in decline. Macro misery has accelerated the growth of online sales, AXA RE claims, but consumers will be reluctant to return to 'real' shopping when the economy picks up. Yet, according to Hammerson's (albeit UK-specific) report, retail spend will increase 26% between now and 2022, primarily (62%) as a result of less profligate but comparatively wealthy over-55s.

The data suggest online migration is neither the dominant nor indeed the only trend driving a retail subsector. After Spain, the worst affected market will be France with a 5.5% loss of sales per unit area – the result of old-fashioned (bricks and mortar) oversupply. In contrast, the UK, despite a projected increase in online sales from €67.7bn in 2012 to €104.6bn in 2016, will see a comparatively modest 1.5% loss.

Oversupply is no less a problem for the much (and pre-emptively) mourned high street. But the multiplicity of trends is even more apparent in its UK incarnation. Scordo, one of the authors of BNP Paribas' annual tenancy risk review, suggests that, at least in the UK, it is impossible to pinpoint a single factor that will determine whether a high street dives, survives or thrives.

"Every high street in the UK is unique – and the reasons for the decline or otherwise tend to be complex. There is usually more than one reason," says Scordo. 

Last year's BNP Paribas risk review found performance in some unlikely – that is, downmarket – suburban locations, especially in the absence of oversupply or a competing nearby development. Get consumers – who have to buy stuff, after all – a reasonable supply of larger assets and a semblance of strategy for a town centre, and you could well have a new investment sub-sub-class. USS is a joint-venture partner in a project to develop a new town centre in the southeast of England, for instance. LGP is negotiating with local authorities to regenerate as yet unidentified town centres on behalf of its UK pension fund investors.

Meanwhile, just to make things more complicated, a potentially provocative challenge to the assumed link between sales and rents comes from German property firm Patrizia, which last month found that rents immediately correlated with sales in Warsaw, Budapest and Prague, but not in mature market capitals. In other words, even ostensibly similar retail assets will not perform alike – or necessarily at the same time.