The impact of alternative wetting and drying technique adoption on technical efficiency empirical evidence from rice production in mekong river delta, vietnam

UNIVERSITY OF ECONOMICS HO CHI MINH CITY VIETNAM ERASMUS UNVERSITY ROTTERDAM INSTITUTE OF SOCIAL STUDIES THE NETHERLANDS VIETNAM – THE NETHERLANDS PROGRAMME FOR M.A IN DEVELOPMENT ECONOMICS THE IMPACT OF ALTERNATIVE WETTING AND DRYING TECHNIQUE ADOPTION ON TECHNICAL EFFICIENCY: EMPIRICAL EVIDENCE FROM RICE PRODUCTION IN MEKONG RIVER DELTA, VIETNAM BY HUYNH NGOC SONG MINH MASTER OF ARTS IN DEVELOPMENT ECONOMICS HO CHI MINH CITY, DECEMBER 2017 UNIVERSITY OF ECONOMICS INSTITUTE OF SOCIAL STUDIES HO CHI MINH CITY THE HAGUE VIETNAM THE NETHERLANDS VIETNAM - NETHERLANDS PROGRAMME FOR M.A IN DEVELOPMENT ECONOMICS THE IMPACT OF ALTERNATIVE WETTING AND DRYING TECHNIQUE ADOPTION ON TECHNICAL EFFICIENCY: EMPIRICAL EVIDENCE FROM RICE PRODUCTION IN MEKONG RIVER DELTA, VIETNAM A thesis submitted in partial fulfilment of the requirements for the degree of MASTER OF ARTS IN DEVELOPMENT ECONOMICS By HUYNH NGOC SONG MINH Academic Supervisor: DR LE THANH LOAN HO CHI MINH CITY, DECEMBER 2017 DECLARATION I hereby declare that this thesis entitled “The impact of alternative wetting and drying technique adoption on technical efficiency: empirical evidence from rice production in Mekong River Delta, Vietnam” has been completely written by myself The study is the result of my own work combined with supervision and guidance from Dr Le Thanh Loan of University of Economics, Ho Chi Minh city, Vietnam I guarantee that the results with all suggestions in this study are fully based on my personal work and knowledge which are strictly followed the disciplines of Vietnam Netherlands Programme This study, or any related documents of this dissertation, has certainly not been submitted for any previous qualifications or any other institutions and resources I am also responsible for all the contents in this research Date: 07 December 2017 Signature: _ Full name: Huynh Ngoc Song Minh i ACKNOWLEDGEMENT The past two year with Vietnam – the Netherlands programme has been such a memorable and special experience in my life I feel truly thankful for all of the knowledge and skills that I have the chance to learn which are extremely important for me to complete this thesis successfully First and foremost, I would like to express the deep gratitude to my supervisor, Dr Le Thanh Loan It has been an honor to be her only master student in Vietnam and the Netherlands programme 22nd course She has been sharing with me the integrant researching experience from collecting data to completing thesis I appreciated all of her contributions of time, ideas, dedicated guidance and support during my thesis process The enthusiasm that she has for this project was extremely motivational for me, even during tough times in this master journey I am also thankful for the excellent example she has provided as a successful woman economist and professor Secondly, I would like to thank the funding from FAO and CGIAR for the project titled "Documenting Adoption of the AWD Water Management Technique in Vietnam" in the MRD, Vietnam in 2016 Furthermore, I also want express my appreciation to Prof Dr Nguyen Trong Hoai, Dr Pham Khanh Nam and all the lecturers as well as the entire associates of Vietnam – the Netherlands Program for their dedication and willingness to support all students in my class Especially, I would like to thank Dr Truong Dang Thuy and Dr Le Van Chon for their valuable suggestions which help me to complete my thesis In addition, I am extremely appreciative the valuable time with my classmates in course 22, particularly, all of the members in my study group, for their encouragement and cooperation during the course After all, I want to express how valuable it was to me for receiving the strongest encouragement and support from my beloved family, especially my mom Because all of their sacrifices which generate the best conditions for me to finish this program and this thesis ii TABLE OF CONTENTS DECLARATION i ACKNOWLEDGEMENT ii TABLE OF CONTENTS iii LIST OF FIGURES v LIST OF TABLES vi ABSTRACT vii ABBREVIATION viii CHAPTER 1: INTRODUCTION 1.1 Problem Statements 1.2 Research Objectives 1.3 Scope of the study 1.4 Structure of the thesis 10 CHAPTER 2: LITERATURE REVIEW 11 2.1 Overview about the AWD technique 11 2.1.1 AWD definition 11 2.1.2 AWD guideline in Viet Nam 13 2.1.3 The AWD score 15 2.1.4 The impact of adopting AWD 16 2.2 Overview about technical efficiency of production function 19 2.2.1 Theory of frontiers production technical efficiency 19 2.2.2 Empirical Technical Efficiency Review 21 2.2.3 Review of Determinants on Technical Efficiency 22 2.3 Summary 23 CHAPTER 3: DATA AND METHODOLOGY 25 3.1 Methodology 25 iii 3.1.1 Conducting the AWD Score 25 3.1.2 Analytical Framework 28 3.1.3 Econometrics Model 31 3.2 Data 34 CHAPTER 4: RESULTS AND DISCUSSION 37 4.1 Descriptive Statistics 37 4.1.1 Data Description 37 4.1.2 Correlation Matrix 40 4.2 Empirical Results 43 4.2.1 The AWD adoption degree and challenges for AWD adoption 44 4.2.2 Results of average technical efficiency of rice production in the MRD region 47 4.2.3 Results of determinants on the technical inefficiency 48 4.3 Discussion 51 CHAPTER 5: CONCLUSION 53 5.1 Main findings 53 5.2 Policy implications 54 5.3 Limitations 54 REFERENCES 56 APPENDIX 63 iv LIST OF FIGURES Figure 2.1: The isoquant for technical efficiency estimation from the inputoriented 20 Figure 2.2: The frontier for technical efficiency estimation from the outputoriented 20 v LIST OF TABLES Table 3.1: The synthesis of signals that farmers use to observed water level on the field during irrigation process 26 Table 4.1: Descriptive Statistics 38 Table 4.2: Correlation Matrix 41 Table 4.3: Variance inflation factor 42 Table 4.4: Correlation Matrix 43 Table 4.5: Percentage of different AWD adoption level 44 Table 4.6: AWD adoption score by provinces 45 Table 4.7: Challenges of AWD adoption in MRD province 46 Table 4.8: Estimated Average Technical Efficiency 47 Table 4.9: The technical inefficiency determinants model 48 Table 4.10: Akaike's information criterion and Bayesian information criterion 50 Table A1: Comparison between estimated results between half-normal and truncated distribution efficiency model 63 vi ABSTRACT One of the most serious issues that potentially lead to total rice yield losses is climate change and its consequence, water scarcity To counteract with this problem, the International Rice Research Institute has developed and promoted the alternate wetting and drying (AWD) water saving technique among rice growing countries to save irrigation water as well as enhance productive cropping However, after widely adopted, farmers have adjusted the technique differently in term of irrigating schedule and practice These realities lead to a problem in measuring the degree of AWD technique adoption at farm level and investigating its impact on rice production From the original AWD score, this study suggests a modified AWD score including water drainage practice to represent for the adoption degree of each farm, based on that AWD application impact on the rice production technical efficiency is also evaluated Using the sample of 250 farms surveyed in Mekong River Delta provinces, the adjusted AWD score is calculated for each farm Subsequently, a Stochastic Frontiers Cobb-Douglas production function is regressed using maximum log likelihood method to measure the technical inefficiency, after which, a function of technical inefficiency determinants is investigated, where AWD score was included as a main factor Results indicate that higher AWD application degree can improve technical efficiency of the production Thus, AWD technique should be continually promoted on large scale adoption and strictly followed IRRI instructions to improve rice production technical efficiency Key words: Alternative wetting and drying technique (AWD), Technical efficiency, Mekong River Delta, Vietnam JEL: Q12, Q15 vii ABBREVIATION PH – Power of hydrogen AWD – The Alternate Wetting and Drying Technique IRRI – The International Rice Research Institute CH4 – Methane MRD – Mekong River Delta 1M5R – One must and five reduction campaign KPA – Kilopascal KG – Kilogram DAS – Days after sowing FGDS – Focus groups discussions KIIS – Key informant interviews VIF – Variance inflation factor BIC – Bayesian information criterion AIC – Akaike information criterion CM – Centimeters viii potential of achieving the maximum amount of output for a certain level of inputs, the rice production with higher AWD degree of adoption, can generate more output from each level of input and the production have higher efficiency This impact of AWD adoption on the efficiency can be explained as adoption of safe AWD is suggested to reduce the amount of input (water) and increase the output or show no significant reduction on the output, thus AWD can improve the efficiency of the production Results of other regressions show that education, experience together with type of soil also statistically and significantly pose negative impact on the technical inefficiency In details, the education’s coefficient is -0.286 indicating that one higher schooling year of household head can reduce the inefficiency of the production by 28.6 percent, holding other things constant The estimated parameter of experience is -0.027, which means when the famers have one more years of experience the inefficiency reduce by 2.7 percent in a significant way, ceteris paribus Moreover, the coefficient of soil is -1.326 suggesting that when the soil is fully alluvial type, technical inefficiency decline by 13.26 percent, holding other things unchanged Parameter of member variable which represents for the number of household member involved in agriculture is insignificantly negative, this mean more member participate in rice production in each household is not necessarily improve the technical efficiency The result also includes the empirical results of variables which belong to the idiosyncratic error term This study adds age and gender of household head into this function because variables affecting the idiosyncratic error term are factors that affect the production but the famers cannot change these characteristics In fact, the result show that both age and gender show negative and statistically significant impacts on idiosyncratic error term Meaning that with both older and male household head, the part include in the idiosyncratic error term of the production function can be improved Finally, the average value of the technical inefficiency part, U sigma is 0.0597 and of the idiosyncratic part, V sigma is 0.142 The estimated Log Likelihood value is 149.2 49 As reviewed in the literature review section, there are three distribution assumptions which are commonly made for the technical inefficiency disturbance of the production function These are half-normal, truncated, and exponential distribution In order to choose the best option for the analysis, all of these three assumptions were tested Firstly, exponential distribution is not appropriate to be used for this dataset Results of both regressions under half-normal and truncated distribution assumption are showed in Table A1 for comparison Generally, in both of these models, the estimated parameters of AWD score in technical inefficiency model are consistently negative, which means higher degree of AWD technique adoption affects technical efficiency in the positive trend However, in half-normal assumption model the effect of AWD score is statistically significant while in truncated assumption model, it is statistically insignificant As to compare which model is more suitable for the dataset, the Log likelihood Ratio test together with the Bayesian information criterion (BIC) and Akaike information criterion (AIC) is applied Firstly, the half normal is a restricted form of the truncated normal with the restriction that the average of 𝑢𝑖 denotes as u = The value of the generalized likelihood ratio statistic in this case is (-18.8) calculated from the given formulation 𝜆 = −2[𝑙𝑛[𝑙(𝐻0 )] − 𝑙𝑛[𝑙(𝐻1 )]] Since the estimated value is negative (and it is less than the critical c2 value, which is always positive), we cannot reject the hypothesis that Ho: u = and accept the model which assumes the half normal distribution Secondly, Akaike's information criterion and Bayesian information criterion test in Table 4.10 helps to choose best maximum log likelihood model, model with the minimum AIC and BIC is the best model which is half-normal distribution model in this case Table 4.10: Akaike's information criterion and Bayesian information criterion Model Log likelihood AIC BIC Truncated Distribution 139.76 -271.52 -257.43 Half-normal Distribution 149.15 -290.31 -276.22 Source: Author’s estimation 50 4.3 Discussion Initially, the AWD is applied in a relatively adoption level among farms in MRD provinces The average AWD score for the entire dataset is 0.65 and most of the score centers in the range of 0.5 to 0.7 The score also shows equivalent in adoption among all of the provinces Nevertheless, there are challenges that might influence the AWD technique adoption in large scale in MRD provinces in general Firstly, less than 70 percent of the famers in this dataset not know or understand AWD technique correctly Instead, they apply the technique spontaneously, which consequently leads to inappropriate practices Secondly, most of the famers not continue using water tube to determine water level on the field, they feel more comfortable with traditional observing methods Thirdly, among provinces the water irrigation sources are different, which might cause difficulty for the farmers to control their irrigation schedule and water level Finally, the major of famers in the MRD province is not consider water scarcity as an important problem in their cultivation activities, which provides less motivation for them to apply the technique resolutely As a consequence, these issues should be noticed and addressed in order to enhance higher degree of adoption for AWD technique in Vietnam and particularly in MRD region Additionally, rice production technical efficiency level is relatively high which shows uniformity among rice producers in the MRD provinces, Vietnam Most of the production is producing closely to the estimated frontier The AWD score in the second regression shows that the effort of adopting this water-saving technique could make the rice production become more efficient, particularly in the MRD provinces, Vietnam This means when famer adopts safe AWD technique at a higher degree which includes keeping their field in alternate flooded and non-flooded condition, irrigating as the instructed threshold, practicing withdraw water, they gain higher technical efficiencies As the technical efficiencies are higher, then with a certain level of inputs they can generate more output Compared to the literature this impacts of AWD on technical inefficiency can be explained as AWD is suggested to reduce water input without causing any yield losses or even increasing grain yield The 51 mechanism behind this impact is that rice is still absorbed enough water through its roots in some growing period without continuously flooding Furthermore, AWD technique can even increase grain yield because this technique hold the root to grow stronger and help the soil become drier, more stable, which reduce harvest losses Consequently, AWD technique should be continually recommended for farmer to adopt in the larger scale and different location, especially where water for irrigation are scarce Also, for each famer, the AWD technique should be applied more appropriately to achieve higher AWD score which could directly affect the technical efficiency Specifically, in the MRD provinces, famers should apply AWD more adequately in term of irrigation timing, instructed irrigated water threshold, and should practice withdrawing water to improve their production In our sample, 271 out of 250 farms are adopting AWD with higher level (the score higher than 0.5) and these farms actually have a higher average technical efficiency The remaining farms in the dataset as well as the whole MRD region should be encouraged and supported to improve their AWD adoption scores in their future crops which consequently help to save more irrigating water and increase technical efficiency of the general production 52 CHAPTER 5: CONCLUSION 5.1 Main findings Alternative wetting and drying is a water-saving irrigation technique that has been developed and promoted to adopt widely in many rice growing countries including Vietnam As the technique is widely adopted, it has also been adjusted differently As a consequence, the degree of adoption for each farm and its suggested impacts can change in various circumstances In order to analyze and determine the level of AWD technique adoption as well as its impact after widely adopted, this study has conducted the general survey with famers in the MRD provinces, Vietnam In this survey, the AWD project team suggested an modified AWD score which reflects the current AWD technique adoption degree of each farming household and collected data to measure the score Furthermore, the data also contains other information which is used to analyses the impact of AWD adoption on rice production in this area Using the technical efficiency concepts, firstly, a stochastic production function is regress to measure technical inefficiency of the production, continually, a regression of AWD score and other determinants is applied to see the impact of AWD on the technical inefficiency of the rice production There are three main findings in this study Firstly, the average AWD adoption score is 0.65 on the scale from to 10 and most of the famers estimated score ranged from 0.5 to 0.7 shows a relatively high and uniformity AWD current adoption state among MRD provinces Moreover, the suggested that lack of understanding about AWD, the absence of the water tube for determining water irrigated level, different in water resource use and farmer perceptive towards water scarcity are the challenges that should be consider to improving the level of AWD adoption The estimated average technical efficiency in this study is 95.7 percent indicates that most of the farms in the dataset produce closely to the frontier Finally, AWD score poses negative impact on the inefficiency, in specific, an increase of 0.01 in the score can reduce inefficiency by 3.745 percent, ceteris paribus, which mean higher degree of AWD adoption can improve the production technical efficiency for famers in the MRD area and this results is explained base on the impact of AWD on reduction 53 of water input without negatively affect the yield or even increase the yield by enhancing stronger root and avoid harvest losses Overall, this study has contributed an adjusted AWD adoption score based on a determined definition of AWD adoption and included the effect of water drainage in Vietnamese AWD practice This measurement helps to define AWD after the technique is generally adopted Furthermore, we also investigate the impact of AWD in rice production after AWD is widely applied by using a new approach base on the concept of technical efficiency 5.2 Policy implications According to the results, the degree of AWD technique adoption is found to have negative and statistically significant impacts on the technical inefficiency of rice production in the MRD provinces, Vietnam AWD technique then should be continually promoted to be widely applied in agricultural policies and programs, specifically for rice production in Vietnam and generally for other rice growing countries, in order to improve their production technical efficiency In addition, compiling with the increase in AWD technique adopting scale, farmer should also be recommended to apply this technique more appropriately based on the “safe AWD” practices and achieve higher AWD score These mentioned practices include three main key points Firstly, famer should keep their field in alternate flooded and non-flooded conditions whenever it is possible to make sure they are applying AWD Secondly, famer should irrigating and applying this technique adequately in term of irrigating schedule and water threshold In detailed, AWD technique is highly encouraged during growing and before harvesting stages, also, a maximum irrigated water level of five centimeters above the field surface and a threshold of 15 centimeters water dropped level below the surface is also empathized for safe AWD Finally, farmer should consider withdrawing water out of the field to enhance faster drying process and warrant AWD is correctly applied 5.3 Limitations 54 Beside the attempt for perfections, the study still contains some inevitable limitations Firstly, since there are only a small number of conducted researches that examined the effect of AWD technique after widely adopted, the measurement options which can proxy for the AWD technique’s adoption degree for each farm are narrow Furthermore, the AWD score suggested in this study has also been modified based on the real practice of famers in MRD provinces, it has not been previously uses by other studies Secondly, this study is also the first research that examines AWD adoption score as a determinant of technical efficiency, consequently, the explanation for the estimated results are mostly based on the research analyses and arguments Thirdly, the water input in the production function is only measured by irrigation times this is not the most appropriate proxy for this input Instead, if further study can capture the exact amount of total water use in the production from two sources including irrigation water and rain fed, the regressed function would be improved Finally, in agriculture industry, including rice production, each amount of different input use is usually estimated base on the size of the farms so the correlations between land and other the input variables are still relatively high, thus when interpreting the effect of other inputs on the total yield the recommended sufficient amount of these input uses for one unit of land should be considered Hence, further studies that are relevant to this topic can develop these elements in order to complete and contribute more understanding about the AWD technique as well as enrich the literature review Nevertheless, this study is hopefully developed and contributed new evidences, findings into the literature of AWD technique adoption’s impact on rice production in Vietnam, and generally of all rice growing countries The results suggest that agricultural policy should put more effort in promoting AWD technique widely for rice producers In addition, the technique should also be applied more adequately with a higher degree adoption score to gain positive impact on efficiency of rice production Finally, the water drainage effect is enhance the drying process of the field 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Agronomy Journal 100(3): 726-734 山口哲由, et al (2016) "Alternate Wetting and Drying (AWD) Irrigation Technology Uptake in Rice Paddies of the Mekong Delta, Vietnam: Relationship between Local Conditions and the Practiced Technology." アジア・アフリカ地域研 究 15(2): 234-256 62 APPENDIX Table A1: Comparison between estimated results between half-normal and truncated distribution efficiency model Half Normal Truncated Stochastic Frontier Model lnyield lnyield lnland 0.7310*** 0.7380*** lnseed 0.0568* 0.0692 lnfertilizer 0.0403 0.0534 lnpesticide 0.0182*** 0.0160*** lnwater -0.0681* -0.0863** lnlabor 0.0170** 0.0193** lnmachine 0.1360* 0.1120** Constant 1.4660** 1.3252*** inefficiency model Sigma U Sigma U AWD score -3.7450** 0.0956 education -0.2860* -0.2660 experience -0.0270*** -0.0323** Member -0.0212 -0.0511 Soil -1.3261*** -1.8940 Sigma V Sigma V Age -0.0452*** -0.0636*** Gender -2.0221*** -1.2130 Determinants of technical Mean U Awd score -1.6930 Number of observations 250 250 Average sigma V 0.1420 0.1300 Average sigma U 0.0597 0.1650 Log likelihood 149.20 139.80 *, **, *** respectively denotes significance level of 10%, 5%, 1% Source: Author’s estimation 63 ... this thesis entitled The impact of alternative wetting and drying technique adoption on technical efficiency: empirical evidence from rice production in Mekong River Delta, Vietnam has been completely... impact of AWD adoption and other determinants on technical efficiency of rice production in MRD provinces 1.3 Scope of the study Under the study topic of: The impact of alternative wetting and. .. ALTERNATIVE WETTING AND DRYING TECHNIQUE ADOPTION ON TECHNICAL EFFICIENCY: EMPIRICAL EVIDENCE FROM RICE PRODUCTION IN MEKONG RIVER DELTA, VIETNAM A thesis submitted in partial fulfilment of the requirements