Tests and confidence intervals for a class of scientometric, technological and economic specialization ratios

In economic, scientometric and innovation research, often so-called specialization indices are used. These indices measure comparative strengths or weaknesses as well as specialization profiles of the observation units with respect to certain criteria, such as patenting and publication or trade activities. They allow question like: is Germany specialized in the export of motor vehicles? Or is the UK specialized in biotech patents? Unfortunately, little is known about their statistical properties, which makes valid inferencing difficult. In this article we prove asymptotic normality for a certain class of scientometric, technological and some economic, though nonmonetary, specialization indices. We provide asymptotic confidence intervals and demonstrate in an example how to obtain statistically sound results. We will also address the problem of normalization of these indicators. All procedures proposed are provided in an add on package for R statistical environment.