Within anarchism, the concept of wage slavery refers to a situation perceived as quasi-voluntary slavery, where a person's livelihood depends on wages, especially when the dependence is total and immediate. It is a negatively connoted term used to draw an analogy between slavery and wage labor by focusing on similarities between owning and renting a person. The term "wage slavery" has been used to criticize economic exploitation and social stratification, with the former seen primarily as unequal bargaining power between labor and capital (particularly when workers are paid comparatively low wages, e.g. in sweatshops) and the latter as a lack of workers' self-management, fulfilling job choices and leisure in an economy. With the advent of the Industrial Revolution, thinkers such as Pierre-Joseph Proudhon and Karl Marx elaborated the comparison between wage labor and slavery in the context of a critique of societal property not intended for active personal use while Luddites emphasized the dehumanization brought about by machines. Emma Goldman famously denounced "wage slavery" by saying: "The only difference is that you are hired slaves instead of block slaves".