Bauhinia blakeana Dunn is the Hong Kong Special Administrative Region emblem and a popular horticultural species in many Asian countries. It was first described as a new species from Hong Kong almost a century ago. Th...Bauhinia blakeana Dunn is the Hong Kong Special Administrative Region emblem and a popular horticultural species in many Asian countries. It was first described as a new species from Hong Kong almost a century ago. This plant is sterile and has long been considered a hybrid, possibly from two related species, B. purpurea and B. variegata. However, not much evidence based on molecular methods was available to support this hypothesis. In this study, sequences of internal transcribed spacer I （ITS1）, rbcL and atpB-rbcL intergenic spacer for five Bauhinia species and two varieties of one of the species were determined and compared. There were two types of ITS1 sequences in B. blakeana, one indistinguishable from that of B. purpurea and the other one identical to that of B. variegata. This confirmed that B. blakeana was a hybrid of these two species. Chloroplast atpB-rbcL intergenic spacer sequence of B. blakeana was identical to that of B. purpurea, indicating that B. purpurea was the female parent. The hybridization event seemed to occur only recently and was a rare incident. Its occurrence was likely facilitated by interspecific pollen competition. It appeared that human efforts played a crucial role in the preservation and ubiquity of B. blakeana.展开更多
Sale before completion(i.e.presale)is a common practice that real estate developers use to sell residential units.Since presale buyers are unable to inspect uncompleted units,developers may take advantage of asymmetri...Sale before completion(i.e.presale)is a common practice that real estate developers use to sell residential units.Since presale buyers are unable to inspect uncompleted units,developers may take advantage of asymmetric information and release information about quality to the market selectively.The search theory also suggests that incomplete pricing information,especially for new products,will induce a less competitive market that is characterised by dispersed presale prices.Would price dispersion be reduced if developers were required to provide more quality and pricing information?In this study,we argue that this is not necessarily the case.We conduct a natural experiment using a new information disclosure ordinance governing first-hand residential sales in the Hong Kong SAR,China.We find that the ordinance reduced the price dispersion of presale units with asymmetric information about property quality,but increased their price dispersion when limited pricing information(e.g.thin trading volume)was available in the neighbourhood.As a critical test,we further show that the ordinance increased price dispersion even more after the units were completed.This suggests that the ordinance has indeed made presale pricing more difficult because developers are no longer allowed to use different strategies to test market demand.展开更多
基金Partially Supported by the Chinese University of Hong Kong Strategic Research Programme.
文摘Bauhinia blakeana Dunn is the Hong Kong Special Administrative Region emblem and a popular horticultural species in many Asian countries. It was first described as a new species from Hong Kong almost a century ago. This plant is sterile and has long been considered a hybrid, possibly from two related species, B. purpurea and B. variegata. However, not much evidence based on molecular methods was available to support this hypothesis. In this study, sequences of internal transcribed spacer I （ITS1）, rbcL and atpB-rbcL intergenic spacer for five Bauhinia species and two varieties of one of the species were determined and compared. There were two types of ITS1 sequences in B. blakeana, one indistinguishable from that of B. purpurea and the other one identical to that of B. variegata. This confirmed that B. blakeana was a hybrid of these two species. Chloroplast atpB-rbcL intergenic spacer sequence of B. blakeana was identical to that of B. purpurea, indicating that B. purpurea was the female parent. The hybridization event seemed to occur only recently and was a rare incident. Its occurrence was likely facilitated by interspecific pollen competition. It appeared that human efforts played a crucial role in the preservation and ubiquity of B. blakeana.
基金This project was financially supported by the General Research Fund[Project Reference:HKU 17201515]Research Grants Council,University Grants Committee.
文摘Sale before completion(i.e.presale)is a common practice that real estate developers use to sell residential units.Since presale buyers are unable to inspect uncompleted units,developers may take advantage of asymmetric information and release information about quality to the market selectively.The search theory also suggests that incomplete pricing information,especially for new products,will induce a less competitive market that is characterised by dispersed presale prices.Would price dispersion be reduced if developers were required to provide more quality and pricing information?In this study,we argue that this is not necessarily the case.We conduct a natural experiment using a new information disclosure ordinance governing first-hand residential sales in the Hong Kong SAR,China.We find that the ordinance reduced the price dispersion of presale units with asymmetric information about property quality,but increased their price dispersion when limited pricing information(e.g.thin trading volume)was available in the neighbourhood.As a critical test,we further show that the ordinance increased price dispersion even more after the units were completed.This suggests that the ordinance has indeed made presale pricing more difficult because developers are no longer allowed to use different strategies to test market demand.
