Ricardo and his co-authors also studied the average forecast across agents, finding weak sensitivity of the average forecast to news and serially correlated forecast errors. Subsequent research, which builds on the work of Mankiw, Reis and Wolfers, has confirmed and refined these findings. It has established that expectations deviate systematically from fullinformation rational expectations.
The strategy of concentrated spatial development in urban concentrations was emulated by the flying geese of Asia mentioned by Venables. The focus of growth in the 1970s and 1980s shifted to the tigers like Singapore, Hong Kong, South Korea and Taiwan. Singapore and Hong Kong being city states naturally exhibited strong natural economic concentration.