The three variables identified by Max Weber as defining social class are life circumstances and opportunities; ownership of property and wealth; and working conditions and markets. Of these, Weber considered the ownership of property to be the most decisive variable in determining class.
Weber argued that property owners were able to influence or even dominate commodity and labor markets. Landowners, for instance, are able to collect rents from tenants, thus transforming their property into wealth.
Weber's third variable applies primarily to the working class, who may be subdivided by their working conditions, earnings and services into classifications of skilled, semi-skilled and unskilled laborers. Taken sequentially, these groups represent diminishing attributions of social value, based on what their members can offer society.