Indirectly all public expenditure aids private industry and commerce. But there are many forms of direct aid, that are treated and regarded as conferring a common benefit on allalike although accruing to the good of certain persons. Bounties are sometimes offered for certain products. Enterprises of various kinds receive subventions. The so-called protective system involves an indirect expenditure of the people's money in the same way. The expense of maintaining the currency, of building and keeping up roads, canals, harbours, and the like is of the same character. So are many public buildings, as exchanges, markets, slaughter-houses, structures and grounds for public fairs and the like, and commissions and other organisations for disseminating knowledge concerning horticulture, agriculture, and various industries. The maintenance of a system of weights and measures, also, belongs here. Besides all those mentioned and some others which are generally treated as expenditures for the common benefit, there are a great many things which the State does for the benefit and assistance of industry and commerce that are regarded as conferring special benefit and treated as such.

The administrative control of private industry and commerce has become a necessity on account of the growing power of modern organisations of capital. The necessity has been widely felt of controlling industrial monopolies, and we have numerous commissions for the regulation of railroads and the like. To this branch of expenditure belongs also the cost of the control exercised for the protection of the public health over the production and sale of foods. This is mainly an expenditure of the local governments, although it occasionally enters into that of the central government, especially in the case of imported foods. The cost of the enforcement of sanitary regulations of all sorts is another expenditure of the same character.