Moreover, the consequences of this credentialization on equality and a policy that might address this inequality are identified. The subject of agency and structure is fundamental for sociology. Agency refers to the purposeful and volitional nature of human activity. Conversely, social structure implies the recurrent patterned arrangements that limit or influence the opportunities and chances available. Essentially, social structure exerts a limiting effect on human activity; agency is the capacity of people to act independently of this. There are a number of structures and agents that would be thought to create a relationship between incarceration and unemployment for each of the 3 explanations. Selection: Selection effects presume that difficulties in employment pre-exist incarceration. Selection is the notion that there is some characteristic of individuals which is correlated between imprisonment and joblessness that could explain the connection between them. According to Pager (51), the types of individuals that wind up in jail do not have adequate skills to get employment, or do not actually want to work. For instance, problems of employment predate imprisonment. Individuals who are in jail on average have low education levels as well as spotty work histories, and the majority of them struggle with drug abuse and health issues. As such, the agency is that people who often end up in jail usually choose not to work and choose not to have high levels of education. On the other hand, structures are the basic requirements that employers look for in candidates regarding particular jobs, for instance university degree, as well as the willingness of the individual to work. The subject of selection is a vital argument against the idea that imprisonment serves to erode job skills since individuals who are not able to get jobs after leaving prison were perhaps unemployable prior to being incarcerated. Agency is seen whereby through their own volitions and before being jailed, people purposely engage in activities and/or behaviours that make them less employable, such as substance abuse or having low education levels. Most of them also have undesirable work histories and struggle with mental problems. With such issues, these people have little job skills and are often unable to secure jobs before entering prison. They will still have difficulties in finding employment after leaving prison since the social structure with regards to employment requires skilled, educated and competent persons; qualifications that many of them do not meet. Transformation: Pager (52) asserted that the experience of incarceration changes a person in ways that prevent him/her from entering the labour market. The agent or agency is people’s capacity to seek jobs and the structure is the social system that places professional restrictions on ex-offenders. Although they desire to get employment, the skills of former inmates have been eroded and they do not have the professional competence that makes them employable. Thus, they end up being unemployed when they leave prison. Essentially, experience in jail transforms the individual making them to be less employable upon being released compared to what they were when they went into prison. Incarceration changes the skills that people have; it erodes job skills. Individuals who are unable to find employment when they are released from jail were perhaps employable before they entered prison.