Since the economic crisis affected the real economy in Romania, the official GDPdeclined by almost 5 percent in 2009 compared with 2008, 1.3 percent in 2010 against the previousyear and unemployment increased too. In 2011 a moderate growth of the GDP is expected butunemployment will further...

Measurement invariance is an important assumption in the Rasch model and mixture models constitute a flexible way of checking for a violation of this assumption by detecting unobserved heterogeneity in item response data. Here, a general class of Rasch mixture models is established and...