We proposes to deal with two major components of structural unemployement: long-term unemployment and repeat unemployement. We shall focus on the interrelations between the two phenomena and on the role played by individual characteristics and labour market institutions. In particular we shall consider institutions such as unemployment insurance unemployment assistance training programs for the unemployed local job offices and firms. The theoretical framework for the analysis are job search models. Job search models present the advantage over competitive explanations of labour market behaviour of alloying for uncertainty and labour market dynamics. We shall test the implications of our model using a panel dataset for Denmark. Panel datasets allow one to follow individuals over time and to register changes in the insitutions and the labour market. The danish panel is unique in Europe for the completeness of the information available and the time span covered. We shall estimate hazard rate models of unemployment duration together with selection into unemployment and training programs; count data models of repeat unemployment; logit and probit models. We expect to be able to draw economic policy conclusions for example on whether unemployment insurance should be experience rated. Learning of new methodologies such as count models; development of already acquired knowledge on duration and binary probability models; deepening of the knowledge of job search modelling; deeper understanding of the working of European labour markets and of the Danish labour market; developing considerations about the impact of institutions on unemployment which may be later applied to the Italian labour market and to other communities labour markets; an increase in the knowledge of long-term unemployment and repeat unemployment. of the policies that could be used to defeat them. At a later stage it may be useful to consult some (danish) firms about their views and reactions concerning experience rated unemployment insurance schemes.