探討歷年台灣養殖漁業生產技術效率之變遷

Investigating the Changes of the Technical Efficiencies of the Aquaculture Production in Taiwan

洪綾憶(Ling-Yi Hung)

指導教授 ： 張宏浩

共同指導教授 ： 蕭清仁(Chiang-Ren Show)

國立臺灣大學/生物資源暨農學院/農業經濟學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.02296

摘要

本研究應用三種不同方法，分別是：資料包絡法、傳統隨機邊界法以及貝氏隨機邊界法來計算各養殖魚種的生產技術效率。首先比較傳統與貝氏隨機邊界法估計的係數值，結果顯示生產函數的估計係數結果一致。至於生產技術效率的機率分配方面，本研究發現不論是哪種魚種，資料包絡法所估計的技術效率的機率分配都較兩種隨機邊界模型估計之技術效率的機率分配來得扁平且右偏。本文進一步利用Kruskal-Wallis檢定法來比較三種不同方法所估計的生產技術效率值的機率分配，結果顯示不同方式所得到的技術效率之分配在統計上是不同的。而各養殖漁戶的排序方面，本研究應用Spearman等級檢定，發現貝氏與傳統的隨機邊界模型都是顯著地高度相關、而資料包絡法與其他兩種隨機邊界法的相關程度則是：石斑魚、文蛤、牡蠣以及鱸魚為顯著高度相關、剩下的魚種為顯著地低度相關。
最後比較不同年間的生產技術效率變化，結果顯示不論是用哪種估計方法，1999年至2000年間有較大的差異，之後有起有落，但差距都不大。若僅使用貝氏的隨機邊界模型比較2000年以及2006年的技術效率差異，則可以發現除了在低技術效率的部分以外，2006年的技術效率在各百分位數都較2000年高；又2006年技術效率值的集中處在0.85以後，但是反觀2000年的技術效率集中處則是在0.5以及0.75之處，這就是造成兩年技術效率差異的原因。

關鍵字

技術效率 ； 養殖漁業 ； 資料包絡法 ； 隨機邊界模型 ； 貝氏定理

並列摘要

The objective of this paper is threefold. First, this paper applies three different methodologies, including Data Envelope Analysis (DEA), classical stochastic frontier analysis and Bayesian stochastic frontier analysis, to estimate technical efficiency of aquaculture farms in Taiwan. In what follows, we compare these three technical efficiencies estimated by these three different methodologies. We conduct the analysis in several steps. We first compare the estimated coefficient of the production function between Bayesian and stochastic production frontier models. In addition, we compare these distributions of technical efficiency by utilizing two different non-parametric methods. To test whether these distributions were the same, the Kruskal-Wallis test is conducted. To further test whether the relative rank of aquaculture farms were consistent between the estimation methods, we use the Spearman Rank test. The final objective of this study is to investigate if the technical efficiency has been changed between 1999 and 2006. First we compare the distribution of technical efficiency obtained from three different methodologies from 1999 to 2006. Finally, we use the results obtained from Bayesian stochastic frontier model to compare the distribution of technical efficiency between 2000 and 2006.
Empirical results show that the coefficients of two stochastic frontier models are almost the same. But when compare the production elasticity, the conclusion is that not only the sigh but the most important input exist slightly differences between two methodologies. In addition, the distribution of technical efficiency estimated by DEA is right-skewed, and flatter than the distribution of technical efficiency estimated by other two methods regardless of the fish types. With respect to the examination if the distributions of technical efficiency were the same, results show that at least two distributions are statistically different. In terms of the relative rank of these aquaculture farms, Bayesian and classical stochastic frontier analysis are statistically correlated, but DEA and two stochastic frontier methodologies are strongly correlated only in some kinds of fish and the others are weakly correlated.
This study analyses the change of technical efficiency across years, and results show that regardless of these different methodologies, there’s a significant differences between 1999 and 2000. After 2000 there’re some up and down in these years, but the scale is minor. Focusing on the change of technical efficiency between 2000 and 2006, results show that when it compares all percentiles, 2006 are higher than 2000. Most importantly, technical efficiencies are centralized around 0.85 in 2006, but centralized around 0.5 and 0.75 in 2000, that’s the reason why technical efficiencies are higher in 2006.

並列關鍵字

technical efficiency ； aquaculture ； Data envelope analysis ； Stochastic frontier analysis

參考文獻

黃貴民、王金利，1997。「臺灣九孔養殖技術效率之分析」，『臺灣水產學會刊』。24卷，3期，251-259。

李武忠、詹滿色、陳郁蕙、陳雅惠、廖一久，2005。「臺灣草蝦養殖產業之技術效率：追蹤資料分析」，『臺灣水產學會刊』，32卷4期，383-390頁。

Balcombe, K., I. Fraser, and J. H. Kim, 2006. “Estimating Technical Efficiency of Australian Dairy Farms Using Alternative Frontier Methodologies.” Applied Economics 38: 2221–2236.

Balcombe, K., I. Fraser, M. Rahman, and S. Laurence, 2007a. ”'Examining the Technical Efficiency of Rice Producers in Bangladesh.” Journal of International Development 19 (1): 1–16.

Bezemer, D., K. Balcombe, J. Davis, and I. Fraser, 2005.” Livelihoods and Farm Efficiency in Rural Georgia” Applied Economics 37(15) : 1737–1745.