Hopi Sen says he's a "cost of living sceptic". He'll not thank me for saying so, but I agree.

First,let's be clear way real wages have fallen. Duncan's right to say that inflation is not to blame, simply because we've seen many periods of inflation around current levels without falling real wages. Blaming inflation for falling real wages is like blaming plane crashes upon gravity.

Nor is it because workers' incomes are being squeezed by more powerful capitalists. In recent years, the share of wages has been more or less flat; this week's figures show that the wage share of GDP is actually slightly higher than it was before the recession.

Instead, real wages have fallen simply because there's a massive excess supply of labour. If we add part-timers who'd like a full-time job and the inactive who'd like to work to the measured unemployed, there are 6.2 million waiting to work more - equivalent to 15.4% of the working age population. And there's an unknown number who are under-employed on the job.

Policies to increase real wages must, therefore, include measures to reduce this excess supply. And herein Labour faces two constraints. One is its commitment to some form of fiscal restraint. The other is that it faces demands (sadly from working class voters too) for "welfare reform", the effect of which would be to strengthen people's incentives to look for work, thus raising the labour supply.

Granted, there is an alternative here* - to raise workers' share of GDP, in ways suggested (pdf) by Howard Reed and Stewart Lansley. But here too, there are big constraints. Policies to increase minimum wages and strenthen collective bargaining would be resisted by capital, and it's possible that even if such measures were enacted, capital would respond by cutting investment and demand for labour; we cannot be confident that wage-led growth is feasible.

All of which brings me to endorse Hopi's point - that Labour's proposals to raise real wages are "small-scale.". He's right to say: "we're setting up a general 'crisis' of living costs, against which our solutions then seem somewhat insignificant."

Herein, I think, lies a reason for Ed Miliband's much-criticized failure to push his economic message; he's aware of this big gulf between the size of the problem and the smallness of his answers.
However, to believe this is due to Miliband's personal, idiosyncratic weaknesses is to commit the fundamental attribution error. Labour's problem isn't a lack of "leadership" but rather that there are serious constraints upon what any social democratic government can achieve.

* You might object that there is one alternative that is very politically feasible - to have tougher immigration controls. However, there's no evidence that these would raise real wages, except slightly at the bottom end of the labour market, and even then only temporarily.