In this paper it is argued that occupational and organizational codes maximizethe correspondence between activities and easily observable characteristics atthe time of their development. Over time the codes become less relevant, leadingto the false impression that the segregation of individuals...

In this paper, I consider the identification of lagged durationdependence in multiple spells without using the assumtion that there are additionalregressors orthogonal to the individual effects. The non-parametricidentification strategy is applied to the multiple non-employment spells of 2066...