1.Ours and Ridder (1992) introduced a novel method to test the hypothesis that firms search sequentially based (in which applicants are screened as they show up) on the relationship between the number of (rejected) job applicants and the number of employees hired. The author used data compiled from filled vacancies for the Netherlands. Different types of search methods were distinguished. The results implied that when firms use advertising, private or 76 public employment agencies, which together cover about 45 per cent of filled vacancies, sequential search is rejected. For about 55 per cent of filled vacancies however, sequential search cannot be rejected. In line with theoretical considerations, when firms use search methods that rely on social networks, sequential search cannot be rejected.
2. Gorter, Nijkamp, and Rietveld, (1993) surveyed the Dutch labor market for recruitment channels and its impact on the vacancy duration. The authors found that labor market segmentation plays an important role in the choice of the recruitment channels; in particular, advertising appears to maximize the difference between expected costs and expected benefits when the vacancy concerned belongs to the primary segment of the labor market, while when it belongs to the secondary segment the preferred recruitment channel seems to be the labor exchange office. By using a piece-wise constant hazard rate, they argued that from the analysis of the time pattern of the hazard rate one may conclude that when advertising is used employers search non-sequentially, while if the informal channel is used employers tend to search sequentially.
3. While Gorter and Ommeren (1994) pushed the analysis one step further. The authors concluded that two main recruitment strategies can be identified: a sequential use of search channels, in which the first search channel chosen is usually the informal channel, and