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For detecting rational bubbles, via relaxing the coefficient constraints of switching regression model, the paper proposes a more efficient model, autoregressive (AR) switching model, and gives the estimation method. An application to seasonally Chinese housing price data in the first decade of 21 century shows the model is more efficient than switching regression model, and provides evidence of bubbles in Beijing and Shanghai, but no evidence of bubbles in Tianjin and Chongqing. Further more, the probabilities of being in survival state show that the real estate-related policies of Chinese government have ruled out bubbles in Beijing, but not in Shanghai. The proposed model can also be used to detect rational bubbles with regime switching structures in other assets. [ABSTRACT FROM AUTHOR]

Cherts and silicified dolostones of the ca. 1600 Ma Dahongyu Formation (uppermost Changcheng Group) from North China contain well-preserved microfossils. Cyanobacteria filaments and coccoids dominate the studied Dahongyu microbiota in the Jixian section. These microfossils show the characteristics of endobenthic, epibenthic, and allochthonous microfossils, which illustrated well a vertical distributional view of an intertidal microbiota. Large numbers and size of allochthonous microfossils are the distinguishing characteristics of this new microbiota. A few of these possess ornaments or odd morphology, which suggest their potential eukaryotic nature. Through regional comparisons, it is revealed that there was significant regional disparity within the Yanshan Basin of microbiotas during deposition of the Dahongyu Formation. The newly studied Dahongyu microbiota is similar to the microbiota from the underlying Changcheng Group, with only slight differences. The absence of typical eukaryotes and the emergence of unique microfossils (especially small fusiform microfossils) make the Dahongyu Formation and the subsequent strata of the Jixian Group distinct from contemporaneous eukaryote-bearing strata.In the Dahongyu assemblage, 19 species were recognized, six species were identified informally and seven species were identified in open nomenclature. One new taxon of microfossil was described: Xiaohongyuia sinica Shi and Feng new genus new species. [ABSTRACT FROM AUTHOR]