Hobsbawn on industrialization, mass mobilization, and “total war” in The Age of Extremes: A History of the World, 1914-1991 (ch. 1):
Jane Austen wrote her novels during the Napoleonic wars, but no reader who did not know this already would guess it, for the wars do not appear in her pages, even though a number of the young gentlemen who pass through them undoubtedly took part in them. It is inconceivable that any novelist could write about Britain in the twentieth-century wars in this manner.
The monster of twentieth-century total war was not born full-sized. Nevertheless, from 1914 on, wars were unmistakably mass wars. Even in the First World War Britain mobilized 12.5 per cent of its men for the forces, Germany 15.4 per cent, France almost 17 per cent. In the Second World War the percentage of the total active labour force that went into the armed forces was pretty generally in the neighborhood of 20 per cent (Milward, 1979, p. 216). We may note in passing that such a level of mass mobilization, lasting for a matter of years, cannot be maintained except by a modern high-productivity industrialized economy, and – or alternatively – an economy largely in the hands of the non-combatant parts of the population. Traditional agrarian economies cannot usually mobilize so large a proportion of their labour force except seasonally, at least in the temperate zone, for there are times in the agricultural year when all hands are needed (for instance to get in the harvest). Even in industrial societies so great a manpower mobilization puts enormous strains on the labour force, which is why modern mass wars both strengthened the powers of organized labour and produced a revolution in the employment of women outside the household: temporarily in the First World War, permanently in the Second World War.
A superior good is something that one purchases more of as income rises. Here it is appealing to, at least metaphorically, see the huge expenditures on industrial armaments as revealing arms as superior goods in this sense.