Over the last few decades, social policies and social services for people experiencing homelessness have focused on increasing their participation in the work force by addressing the factors that prevent full participation. These factors include drug and alcohol use and abuse, mental health, physical disability and a lack of human capital (the set of skills which an employee acquires on the job, through training and experience, which increase that employee's value in the marketplace). In this sense, employment issues discussed within homelessness research have been limited to addressing the relationship between maintaining employment and individual deficits of people experiencing homelessness.