Market Diffusion with Consumer-Based Bilateral Learning

This paper analyzes the market diffusion of a new product whose quality is uncertain. Consumers learn the product quality by observing the history of market outcomes. Firms cannot observe how consumers evaluate the product quality; instead, they learn by observing consumer behavior. New entry occurs gradually because of informational externalities. This dual uncertainty contributes to an S-shaped diffusion of the new product with declining prices.Experience Goods; Quality Uncertainty; Bilateral Learning; S-shaped Diffusion.

ダイ40ジ ニホン ナンキョク チイキ カンソクタイ エットウ ホウコク 1999-2000

第40次日本南極地域観測越冬隊40名は,1999年2月1日から翌2000年1月31日までの1年間,昭和基地で越冬し,第期5カ年計画3年次の観測・設営計画を遂行した.越冬観測の枠組みは第38-39次隊と同じく,定常観測(電離層,気象,潮汐)と,宙空,気水圏,地学,生物・医学の4分野におけるプロジェクト研究観測とモニタリング研究観測から成る.多くの継続観測に加えて,年次計画に従い,新たな観測も開始した.電離層部門では,50MHz・112MHzオーロラレーダ観測およびVLF電波観測を再開した.気象部門では,エアロゾルゾンデを計8回飛揚し,極域成層圏雲の観測に成功した.宙空部門では,第1HFレーダおよびMFレーダのアンテナを更新・新設し,連続運用を開始した.また,新たにナトリウム温度ライダーを設置した.気水圏部門では,温室効果気体の連続観測,エアロゾル観測などを継続した.地学部門では,地震計,超伝導重力計,GPS観測などを維持するとともに,VLBI観測をほぼ月1回の頻度で実施した.生物部門では,沿岸露岩域の湖沼調査(夏期の潜水2回を含む),ならびに小型データロガーを用いたウェッデルアザラシの遊泳行動調査などを実施した.越冬中の内陸調査としては,みずほ基地往復とドームふじ観測拠点(旧名称 : 現在はドームふじ基地)・やまと航空拠点を往復する広域トラバースを実施した.後者の100日間を越えるトラバースでは,物質循環を探る雪氷試料採取,氷床流動量測定のための精密GPS測位,3周波アイスレーダによる氷床内部・基盤地形観測などの成果をあげた.一方,設営関係では,昭和基地整備計画(10カ年)の8年目として,夏隊と協力して第2夏期隊員宿舎建設,300k VA2号発電機と熱源供給システムの更新整備,汚水処理棟設備の立ち上げ,太陽光パネル増設,ヘリポート道路整備などの基地整備作業を実施するとともに,不要建物の解体撤去も行った.越冬期間中は,基地設備の維持管理と安全対策,観測オペレーション支援に力を注いだ.1998年1月に「南極地域の環境保護に関する法律」が発効し,第40次隊から梱包材等の屋外焼却が実質的に全面禁止となった.これらの処理や残置廃棄物を持ち帰るための作業に多くの人手と時間を費やした.第40次隊では合計136t(うち大型98t)の廃棄物を国内に持ち帰った.The 40th Japanese Antarctic Research Expedition (JARE-40) wintering party, with 40 members, has successfully conducted the third-year project of the Vth five-year JARE program, over the period from 1st February 1999 to 31st January 2000, at Syowa Station, Antarctica.The framework of the JARE-40 wintering party program was the same as those of JARE-38 and JARE-39, comprising three routine observation programs and project/monitoring research observation programs in upper atmospheric physics, atmospheric sciences and glaciology, geophysics, and biology. In addition to many continuing projects, several new observations were started: 50MHz/112MHz aurora radars and a VLF wave receiver as part of the ionosphere program, aerosol sonde observations of Polar Stratospheric Clouds (PSCs) as part of the meteorological program, HF/MF radars as part of the upper atmospheric physics program, frequent VLBI experiments as part of the geophysics program, and biological field surveys (including two dives), including monitoring of the undersea behavior of Weddell seals using bio-logging devices.In terms of inland field surveys, two parties were organized: fuel transportation and glaciological/meteorological observations along the route to Mizuho Station in August-September and to Dome Fuji/Yamato air-basecamp in November-January. These surveys involved snow sampling, precise GPS positioning, and sub-glacial surveys using three types of ice radar.Logistical activities, conducted in cooperation with the JARE-40 summer party, included the construction of a second summer lodge, the startup of a second 300 kVA generator and co-generator system, the development of a sewage plant, solar power panels, an access road to the A-heliport, and the cleanup of disused buildings. During the wintering period, efforts were directed towards the maintenance of all facilities at Syowa Station, safety management, and practical support for field operations.The Antarctic Environmental Protection Law came into force in January 1998. Since this time, the outdoor burning of all packaging materials has been restricted at Syowa Station; consequently, we sent a large amount of waste (136t, including 98t of large-size material) back to Japan onboard the RV Shirase

Free Entry, Market Diffusion, and Social Inefficiency with Endogenously Growing Demand

* Revised： [11-04, 2011

Verification of scenario for substorm ignition in the M-I coupling region

第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月16日（水） 統計数理研究所 セミナー室

Long-term variations in electric conductivities measured by the EISCAT Tromsoe UHF radar

第6回極域科学シンポジウム[OS] 宙空圏11月16日（月）　国立極地研究所 2階 大会議

Variations of cosmic noise absorption (CNA) by energetic electron precipitation (EEP) and changes of the auroral morphology

The Tenth Symposium on Polar Science/Ordinary sessions: [OS] Space and upper atmospheric sciences, Wed. 4 Dec. / Institute of Statistics and Mathematics (ISM) Seminar room 2 (D304) (3rd floor