Local industrialization gives an added impetus to the commercialization of services which were formerly carried out within the subsistence economy as social duties. Customs of mutual aid and communal cooperation, even among kinfolk, tend to be undermined by the penetration of the exchange system upon which development of secondary industry necessarily depends. With increased competition and individualism, a decline in communal spirit and village solidarity seems on occasion to have been part of the social price paid for expansion of industry.