The impact which the intensification of agricultural production had on the economy as a whole needs careful consideration. The developments which have already been outlined show that the revenues which the state and powerful landowners derived from agriculture must have increased considerably from the tenth century onwards. Their scope for expenditure was extended and an outline of their main requirements will provide a useful guide to the possibilities for the development of commodity production, the role of commercial markets in the economy and more generally its capacity for expansion. The pattern of demand in the Byzantine economy has to be defined overwhelmingly in terms of consumption. The main requirements were diet, clothing and building and, as has been mentioned already, the emphasis on selfsufficiency reflected the realities of an economy consisting predominantly of direct producers operating on a small scale and having a very restricted commercial sector. Both landowners and peasants obtained as large a proportion of their produce as possible from their own estates, although wealthy landowners were also able to indulge their taste for scarcer items, which were expensive and therefore had a considerable prestige value. Investment played a very minor role. Although no precise figures are available, it is certain that the improvements made by landowners to their properties accounted for only a small proportion of their total expenditure, and their involvement in industry and commerce was also very restricted. Spending by the state was also heavily directed towards consumption. The main exception, and a very important economic factor, was its military expenditure.