Introduction: the growth of inputs

Any increase of the silk production needs an equivalent growth of the output of cocoons or, more precisely, of their silk content. And, of course, the production can grow either because more inputs are allocated to sericulture or because their productivity grows. There is no doubt that in the very long run, growth of inputs accounted for most of the increase in silk production, while sericulture spread from its North China cradle all over the world. The process was still going on, though at a reduced pace, in the nineteenth century and even in the twentieth. New production began in areas such as Kashmir in the 1880s-1890, Mysore in the 1910s–1920s, Brazil in the 1930s. Besides, the geographical boundaries of many sericultural areas were expanding. In Japan the share of the six core districts fell from more than a half of the total in the 1870s to about a third in 1929 because sericulture spread to the whole Honshu island. Nation-wide, the number of silkworm raising families rose from 800,000 (i.e. one out of four) in the 1880s to more than 2 million (i.e. one out of three) in the late 1920s, and the mulberry acreage from 235,000 to more than 600,000 ha. (i.e. from one ninth to one fifth of total cultivatable land). In China, sericulture expanded in new provinces, Shansi, Hupeh, Szechwan in the centre and in Kwangsu in the south.