This paper studies airlines＇ competitive behavior in the U.S. airline in- dustry, focusing on 2014 data. I use a structural model to estimate demand and test several supply models, including noncooperative competitio...This paper studies airlines＇ competitive behavior in the U.S. airline in- dustry, focusing on 2014 data. I use a structural model to estimate demand and test several supply models, including noncooperative competition, perfect collusion, and tacit coordination. There are three different types of tacit coordination, formed by multimarket contact, common ownership, and codeshare agreement, respectively. I find that the model that fits the data best is a tacit coordination model with coalitions between airlines with at least 30% of their markets overlapped and using price rather than quantity as the strategic variable. I further analyze the consumer welfare loss, each carrier＇s profit gains, and changes in market variables due to the tacit coordination.展开更多
Groundwater is the primary water source in the Kingdom of Saudi Arabia. As result of lack of basic knowledge on irrigation practices, massive abstractions of groundwater occurred in 1980＇s. A Decision Support Linear ...Groundwater is the primary water source in the Kingdom of Saudi Arabia. As result of lack of basic knowledge on irrigation practices, massive abstractions of groundwater occurred in 1980＇s. A Decision Support Linear Goal Programming （LGP） model was developed to determine optimal groundwater irrigation levels, to assess the implications for water management policies, and to estimate welfare impact on producer surplus. Due to the reductions of groundwater in 1980＇s, the Al-Wajid aquifer water levels have dropped in agricultural areas by more than 200 m. Results from this study estimate that the total groundwater of the Al-Wajid aquifer that can be saved is equal to 66 MCM for the first scenario, 147 MCM for the second scenario, and 229 MCM for the third scenario. Regarding the welfare analysis impacts, it is clear that the total gross margin is decreasing up to 7.7% at the end of the year of scenario Ⅲ. Therefore, the third scenario with a water saving increase to 18.1% is recommended as a directive for agricultural policy formation in the future.展开更多
文摘This paper studies airlines＇ competitive behavior in the U.S. airline in- dustry, focusing on 2014 data. I use a structural model to estimate demand and test several supply models, including noncooperative competition, perfect collusion, and tacit coordination. There are three different types of tacit coordination, formed by multimarket contact, common ownership, and codeshare agreement, respectively. I find that the model that fits the data best is a tacit coordination model with coalitions between airlines with at least 30% of their markets overlapped and using price rather than quantity as the strategic variable. I further analyze the consumer welfare loss, each carrier＇s profit gains, and changes in market variables due to the tacit coordination.
文摘Groundwater is the primary water source in the Kingdom of Saudi Arabia. As result of lack of basic knowledge on irrigation practices, massive abstractions of groundwater occurred in 1980＇s. A Decision Support Linear Goal Programming （LGP） model was developed to determine optimal groundwater irrigation levels, to assess the implications for water management policies, and to estimate welfare impact on producer surplus. Due to the reductions of groundwater in 1980＇s, the Al-Wajid aquifer water levels have dropped in agricultural areas by more than 200 m. Results from this study estimate that the total groundwater of the Al-Wajid aquifer that can be saved is equal to 66 MCM for the first scenario, 147 MCM for the second scenario, and 229 MCM for the third scenario. Regarding the welfare analysis impacts, it is clear that the total gross margin is decreasing up to 7.7% at the end of the year of scenario Ⅲ. Therefore, the third scenario with a water saving increase to 18.1% is recommended as a directive for agricultural policy formation in the future.
