We extend the Baye and Morgan (2001) model to study competition between price comparison sites in the information market on the internet. We identify one symmetric sub-game perfect Nash equilibrium in which (1) price comparison sites set the same advertising fees; (2) the same proportion of consumers subscribe to each site; (3) each firm mixes between advertising on all sites and not advertising; and (4) advertised prices are dispersed. The introduction of additional price comparison sites may reduce social welfare and joint profits of price comparison sites. In the equilibrium with each consumer subscribing to one site, as the number of price comparison sites goes to infinity, the information market approaches that without price comparison sites.
The standard literature on working time has modelled the decisions of firms in a deterministic framework in which firms can choose between employment and overtime (given mandated standard hours). Contrary to this approach, we consider the impact of uncertainty and real options on the decision of working time and examine the determinants of employment and hours in a stochastic framework. A number of simulation exercises to illustrate the workings of the model are also undertaken.
Labour market regulations aimed at enhancing job-security are dominant in several OECD countries. These regulations seek to reduce dismissals of workers and fluctuations in employment. The main theoretical contribution is to gauge the effects of such regulations on labour demand across establishment sizes. In order to achieve this, we investigate an optimising model of labour demand under uncertainty through the application of real option theory. We also consider other forms of employment which increase the flexibility of the labour market. In particular, we are modelling the contribution of temporary employment agencies (Zeitarbeit) allowing for quick personnel adjustments in client firms. The calibration results indicate that labour market rigidities may be crucial for understanding sluggishness in firms' labour demand and the emergence and growth of temporary work.
microRNAs (miRNAs) form an evolutionarily conserved and highly abundant class of non-coding RNAs that are 21–24 nucleotides (nt) in length. They are processed from double-stranded (ds) RNA precursors and sequence-specifically guide posttranscriptional gene silencing. The processing steps are facilitated by members of the RNAse III enzyme family, whereas gene silencing events are mediated by members of the highly conserved Argonaute (Ago) protein family. Initially discovered in Caenorhabditis elegans, in which they are essential for proper developmental timing, hundreds of miRNAs have been discovered to date in a variety of different organisms, including plants, flies and mammals. Expression profiling approaches demonstrated that miRNAs are specifically expressed not only during embryonic development, but also during cell differentiation and other cellular events such as hormonal signaling. Although miRNAs have been the object of extensive research in recent years, very little is known about their target mRNAs. Their identification along with a comprehensive description of the miRNA/target-mRNA interaction network will add a new level to our knowledge of gene regulation and will also provide new insights into the biology of so far poorly understood diseases, including various forms of cancer.