The time when investors should worry is when private operators control a really substantial slice of any market. That is why the UK Care home sector looks so awful and why the German lab test sector looks vulnerable.

It is when the private sector has become totally dominant as a supplier that it starts to become really vulnerable to price cuts. Until then in most markets private operators are protected by the inefficiencies in the public and not for profit sectors.

The big French care home operators, for instance, point out that they only hold 20% of the market. German private hospital operators hold under 20%.

The danger starts when regulators see that a sector has passed entirely into private hands. That is when they can really start squeezing the gonads. Hence the problems in the Australian lab space.

UK local authorities can put through swingeing cuts on care home tariffs safe in the knowledge that Joe Public will blame private sector providers, not the state for any shortcomings in service.

So which sectors look most vulnerable? The answer is dialysis in many markets, the German lab market and imaging in Portugal – where there has just been a 12.5% cut.

Of course, the rule doesn’t always apply. A dual tariff structure where the private sector officially gets less means there is no protection. So French and Italian hospital operators have been squeezed badly.

And you can only squeeze the private sector if it is mainly in the hands of nasty private equity houses. Attempts to dramatically reduce lab test prices in France and Switzerland hit doctors and other medical staff where it hurt and so led to serious demonstrations.

But the more a sector is industrialised by capitalist forces the more vulnerable it becomes.