The Nature of the Hall Insulator
  We have conducted an experimental study of the linear transport properties of the magnetic-field induced insulating phase which terminates the quantum Hall (QH) series in two dimensional electron systems. We found that a direct and simple relation exists between measurements of the longitudinal resistivity, $\rho_{xx}$, in this insulating phase and in the neighboring QH phase. In addition, we find that the Hall resistivity, $\rho_{xy}$, can be quantized in the insulating phase. Our results indicate that a close relation exists between the conduction mechanism in the insulator and in the QH liquid. 
D. Shahar, D.C. Tsui, M. Shayegan, J.E. Cunningham, E. Shimshoni, S.L.   Sondhi