AN EMPIRICAL STUDY OF COMMON PROPERTY RESOURCE: THE CASE OF SKIPJACK FISHERY IN THE WESTERN-CENTRAL PACIFIC OCEAN

A dynamic Cournot game model is used to predict the strategic behavior of harvesters engaged in a non-cooperative fishery on a common property resource. The model predicts that an increase in the current number of harvesters in a common property fishery will reduce both the equilibrium harvest level and the current resource rent for the individual harvester. Also, an increase in the future number of harvesters increases both two equilibrium levels. These predictions are tested using data from the Japanese skipjack fishery in the Western-central Pacific Ocean. The empirical results on the effect of changes in the current and future numbers of harvesters on the individual harvest rates and resource rent are consistent with theory.Resource /Energy Economics and Policy,

ANALYSIS OF A HIGHLY MIGRATORY FISH STOCKS FISHERY: A GAME THEORETIC APPROACH

This paper develops a two-period noncooperative game-theoretic model of a Highly Migratory Fish Stocks (HMFS) fishery. In each period, the fish stock migrates from the Exclusive Economic Zone (EEZ) of a coastal state into the high seas, where distant water fishing (DWF) harvesters may harvest. We show that having an EEZ improves total welfare by reducing total harvest and that the degree of the welfare improvement increases when the number of harvesters in an HMFS fishery increases. We also show that an increase in the number of DWF harvesters leads to a larger harvest and rent dissipation. With open-access in the second stage, resource rent is totally dissipated for DWF harvesters, but not for the coastal state harvesters, which still earn positive rent.Resource /Energy Economics and Policy,

Common property fisheries resources : a game theoretic and empirical analysis

This dissertation contains theoretical and empirical analyses on common property fisheries resources. The theoretical analysis focuses on a highly migratory fish stocks (HMFS) fishery, and examines the inefficiency caused by non-cooperative harvest. The empirical analysis focuses on a high seas fishery and conducts an empirical test on the effects of the current and future number of harvesters on equilibrium harvest and resource rents. In the theoretical analysis, a two period, non-cooperative, game-theoretic model is developed for an WvIFS fishery. In each period, the fish stock migrate from the exclusive economic zone (EEZ) of a coastal state into the high seas, where distant-water fishing (DWF) harvesters may harvest them. It is shown that having an EEZ improves total welfare by reducing total harvest and the degree of the welfare improvement increases when the number of harvesters in an HMFS fishery increases. It is also shown that new entrants to an HMFS fishery lead to a larger harvest and rent dissipation. With open- Redacted for Privacy access in the second stage, resource rent is totally dissipated for DWF harvesters but not for the coastal state harvesters, which still earn positive rent. In the empirical analysis, a dynamic Cournot model is used to predict the strategic behavior of harvesters engaged in a non-cooperative fishery on a common property resource. The model predicts that an increase in the current number of harvesters in a common property fishery will increase the collective equilibrium harvest level, but will reduce both the equilibrium harvest level and the current resource rent for the individual harvester. Also, an increase in the future number of harvesters increases all three equilibrium levels. These predictions are tested using data from the Japanese trawl fishery in the Bering Sea Donut Hole. The empirical results on the effect of changes in the current and future numbers of harvesters on the collective and individual harvest rates and resource rents are consistent with theory

Is Shrimp Farming in Thailand Ecologically Sustainable?

Shrimp farming in Thailand is considered to be one of the main causes of mangrove deforestation. The Environmental Kuznets Curve (EKC) hypothesis, however, posits that economic development eventually reverses resource degradation. This hypothesis is examined using pooled data on mangrove loss and Gross Provincial Product (GPP) from 23 provinces in Thailand in various years between 1975 and 2004. The empirical results show strong evidence of an EKC relationship between mangrove loss and GPP. In addition, the relationship between shrimp farming and mangrove loss is examined. Shrimp farming is found to significantly affect the extent of mangrove deforestation. The development of extensive and semi-intensive shrimp farming techniques quickens mangrove deforestation, but intensive shrimp farming, which developed during the 1990s, reduces mangrove loss.Keywords: Mangrove Deforestation, Environmental Kuznets Curve, Extensive and Intensive Shrimp Cultur

カンキョウ クズネッツ キョクセン カセツ ニ カンスル ロンブン サーベイ

「環境クズネッツ曲線（EKC）仮説」とは，環境破壊と所得との間に逆Ｕ字型の関係が存在するという仮説である。それは経済発展の初期段階では環境汚染は進行していくが，経済発展がさらに進むと環境汚染は逆に改善されていくことを意味する。この仮説は1970 年代から議論されてきた「成長の限界」の問題に対する反証仮説であったがゆえに大きな関心を集め，1990 年代初頭から多くの研究者によってその実証が試みられてきた。本稿ではこのEKC 仮説に関する実証及び理論研究についてのサーベイを行なう。これまでの実証研究では，健康に直接影響を与える大気汚染物質（SO2，SPM，CO，NOx）でEKCの存在が示され，健康にそれほど直接影響を与えない地球規模の大気汚染物質（CO2）では示されていない。水質汚染物質ではいくつかの指標でEKC が証明されたが，多くの研究では証明されていない。その他の環境質指標でもほとんどの研究でEKC は証明されていない。一方で森林破壊については多くの研究でEKC の存在が確認されている。分析結果は使用される環境質指標，国や地域，推定モデル，推定方法，モデルに含まれる説明変数，時間スパンなどの違いによって多種多様である。推計されたEKC 分岐点（環境汚染の増大から減少へと逆転する点）は，環境汚染指標では3000 ドルから1 万ドル，森林破壊では5000 ドルから8000 ドルの範囲内に存在する（1985 年ＵＳドル基準）。さらにEKCが存在する要因として，経済成長，経済規模，財価格，国際貿易，経済的構造の変化，政治的・社会的制度や政策，人口成長率，人口密度などが明らかにされている

Is Shrimp Farming in Thailand Ecologically Sustainable?

Shrimp farming in Thailand is considered to be one of the main causes of mangrove deforestation. The Environmental Kuznets Curve (EKC) hypothesis, however, posits that economic development eventually reverses resource degradation. This hypothesis is examined using pooled data on mangrove loss and Gross Provincial Product (GPP) from 23 provinces in Thailand in various years between 1975 and 2004. The empirical results show strong evidence of an EKC relationship between mangrove loss and GPP. In addition, the relationship between shrimp farming and mangrove loss is examined. Shrimp farming is found to significantly affect the extent of mangrove deforestation. The development of extensive and semi-intensive shrimp farming techniques quickens mangrove deforestation, but intensive shrimp farming, which developed during the 1990s, reduces mangrove loss

AN EMPIRICAL STUDY OF COMMON PROPERTY RESOURCE: THE CASE OF SKIPJACK FISHERY IN THE WESTERN-CENTRAL PACIFIC OCEAN

A dynamic Cournot game model is used to predict the strategic behavior of harvesters engaged in a non-cooperative fishery on a common property resource. The model predicts that an increase in the current number of harvesters in a common property fishery will reduce both the equilibrium harvest level and the current resource rent for the individual harvester. Also, an increase in the future number of harvesters increases both two equilibrium levels. These predictions are tested using data from the Japanese skipjack fishery in the Western-central Pacific Ocean. The empirical results on the effect of changes in the current and future numbers of harvesters on the individual harvest rates and resource rent are consistent with theory