The act of spending time to look for employment. Job search is used to model an imperfect labour market that does not clear instantaneously because of incomplete information, or search frictions. In a typical model an unemployed (or employed) individual encounters sequential job offers and has to decide whether or not to accept an offer, using certain criteria, e.g. comparing the wage and the imperfectly observed working conditions, associated with the offer, with his or her reservation wage (or current wage). This approach is used to explain the observed patterns in labour mobility and persistence in unemployment.