Industrialism has influenced family structure in several ways. It affects the formation of families and causes demographic variations based on socioeconomic status, like the ages at which spouses marry. Industrialism also lessens the importance of extended families for higher status families. The influence of industrialism extends to family roles - the role of husbands is most directly impacted as they work outside the home, and industrialism provides jobs for married women while also changing their traditional roles. In post-industrial society, the economy shifts from manufacturing to the service sector, knowledge becomes a key asset, and producing ideas drives economic growth.