Embed Size (px)
Citation preview
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
A Search for Structural Breaks in AgricultureEconomy since Independence
Mid Term Progress
Anirudh Jayaraman 1
1M.Sc EconomicsIndira Gandhi Institute of Development Research
October 14, 2016
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Outline
1 Exploring for BreakpointsObjectiveMotivation
2 Data and MethodologyBai and Perron (2003) TechniqueData
3 Summary
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Outline
1 Exploring for BreakpointsObjectiveMotivation
2 Data and MethodologyBai and Perron (2003) TechniqueData
3 Summary
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Objective
Has the Agricultural Sector undergone any significantstructural changes since Independence?
After ’91 reforms?
Need to search for crucial turning points in agriculturalproductivity... CROP WISE.
The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Objective
Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?
Need to search for crucial turning points in agriculturalproductivity... CROP WISE.
The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Objective
Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?
Need to search for crucial turning points in agriculturalproductivity...
CROP WISE.
The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Objective
Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?
Need to search for crucial turning points in agriculturalproductivity... CROP WISE.
The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Objective
Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?
Need to search for crucial turning points in agriculturalproductivity... CROP WISE.
The results may be useful for understanding performancetrends for different crops.
This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Objective
Has the Agricultural Sector undergone any significantstructural changes since Independence? After ’91 reforms?
Need to search for crucial turning points in agriculturalproductivity... CROP WISE.
The results may be useful for understanding performancetrends for different crops.This may help in identifying crops that might have havebeen responsible for acceleration / deceleration inperformance.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Outline
1 Exploring for BreakpointsObjectiveMotivation
2 Data and MethodologyBai and Perron (2003) TechniqueData
3 Summary
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Issues and Motivation
Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.
These turning points are often considered uniformlyacross states, agro-climatic zones and crops.
It may be possible that different crops underwentsignificant structural changes in different years.
Break dates may also end up changing with more recentdata becoming available.
A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.
The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Issues and Motivation
Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.
These turning points are often considered uniformlyacross states, agro-climatic zones and crops.
It may be possible that different crops underwentsignificant structural changes in different years.
Break dates may also end up changing with more recentdata becoming available.
A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.
The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Issues and Motivation
Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.
These turning points are often considered uniformlyacross states, agro-climatic zones and crops.
It may be possible that different crops underwentsignificant structural changes in different years.
Break dates may also end up changing with more recentdata becoming available.
A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.
The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Issues and Motivation
Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.
These turning points are often considered uniformlyacross states, agro-climatic zones and crops.
It may be possible that different crops underwentsignificant structural changes in different years.
Break dates may also end up changing with more recentdata becoming available.
A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.
The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Issues and Motivation
Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.
These turning points are often considered uniformlyacross states, agro-climatic zones and crops.
It may be possible that different crops underwentsignificant structural changes in different years.
Break dates may also end up changing with more recentdata becoming available.
A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data.
The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Issues and Motivation
Researchers often end up choosing sub-periodsexogenously on the basis of prior information abouttiming of significant changes.
These turning points are often considered uniformlyacross states, agro-climatic zones and crops.
It may be possible that different crops underwentsignificant structural changes in different years.
Break dates may also end up changing with more recentdata becoming available.
A relatively recent econometric technique from Bai andPerron (2003) allows us to dynamically learn break datesfrom the data. The strucchange package in R uses aprocedure outlined by Zeileis et al (2005) for thispurpose.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Outline
1 Exploring for BreakpointsObjectiveMotivation
2 Data and MethodologyBai and Perron (2003) TechniqueData
3 Summary
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Bai and Perron (2003)
This procedure is concerned with testing deviations fromstability in the classical linear regression modelyi = xTi β + ui
Assume m breakpoints with the coefficients shifting fromone stable regression relationship to another. Thusthere are m + 1 segments in which the regressioncoefficients are constant.
The algorithm for computing the optimal breakpointsgiven the number of breaks is based on a dynamicprogramming approach. The underlying idea is that ofthe Bellman principle.
Underlying Model (m breakpoints)
yi = xTi βj + ui(i = ij−1 + 1; j = 1,...,m+1)
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Bai and Perron (2003)
This procedure is concerned with testing deviations fromstability in the classical linear regression modelyi = xTi β + uiAssume m breakpoints with the coefficients shifting fromone stable regression relationship to another. Thusthere are m + 1 segments in which the regressioncoefficients are constant.
The algorithm for computing the optimal breakpointsgiven the number of breaks is based on a dynamicprogramming approach. The underlying idea is that ofthe Bellman principle.
Underlying Model (m breakpoints)
yi = xTi βj + ui(i = ij−1 + 1; j = 1,...,m+1)
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Bai and Perron (2003)
This procedure is concerned with testing deviations fromstability in the classical linear regression modelyi = xTi β + uiAssume m breakpoints with the coefficients shifting fromone stable regression relationship to another. Thusthere are m + 1 segments in which the regressioncoefficients are constant.
The algorithm for computing the optimal breakpointsgiven the number of breaks is based on a dynamicprogramming approach. The underlying idea is that ofthe Bellman principle.
Underlying Model (m breakpoints)
yi = xTi βj + ui(i = ij−1 + 1; j = 1,...,m+1)
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Bai and Perron (2003)
This procedure is concerned with testing deviations fromstability in the classical linear regression modelyi = xTi β + uiAssume m breakpoints with the coefficients shifting fromone stable regression relationship to another. Thusthere are m + 1 segments in which the regressioncoefficients are constant.
The algorithm for computing the optimal breakpointsgiven the number of breaks is based on a dynamicprogramming approach. The underlying idea is that ofthe Bellman principle.
Underlying Model (m breakpoints)
yi = xTi βj + ui(i = ij−1 + 1; j = 1,...,m+1)
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Outline
1 Exploring for BreakpointsObjectiveMotivation
2 Data and MethodologyBai and Perron (2003) TechniqueData
3 Summary
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Data
The data has been obtained from Data Bank onAgriculture and Allied Sectors in the PlanningCommission website and is sourced from Directorate ofEconomics and Statistics (DES) and Ministry ofAgriculture.
Yield data of principal crops (All-India) since 1950.These are some 26 crops including rice, wheat, jowar,bajra, maize, pulses (disaggregated), cotton, sugarcane,jute, etc.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
Data
The data has been obtained from Data Bank onAgriculture and Allied Sectors in the PlanningCommission website and is sourced from Directorate ofEconomics and Statistics (DES) and Ministry ofAgriculture.
Yield data of principal crops (All-India) since 1950.These are some 26 crops including rice, wheat, jowar,bajra, maize, pulses (disaggregated), cotton, sugarcane,jute, etc.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
To conclude...
Intend to explore for breaks endogenously in agriculturaltime series data.
Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.
Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.
Outlook
Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
To conclude...
Intend to explore for breaks endogenously in agriculturaltime series data.
Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all.
∴ look at breaksin yields of principal crops for more granular level detail.
Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.
Outlook
Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
To conclude...
Intend to explore for breaks endogenously in agriculturaltime series data.
Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.
Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.
Outlook
Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
To conclude...
Intend to explore for breaks endogenously in agriculturaltime series data.
Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.
Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.
Outlook
Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
To conclude...
Intend to explore for breaks endogenously in agriculturaltime series data.
Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.
Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.
Outlook
Based on break-dates, one can build further hypothesesas to what might have caused those breaks.
It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Exploring forBreakpoints
Objective
Motivation
Data andMethodology
Bai and Perron(2003)Technique
Data
Summary
To conclude...
Intend to explore for breaks endogenously in agriculturaltime series data.
Studies on structural breaks in growth rates of agriculturalGDP may not be the be-all and end-all. ∴ look at breaksin yields of principal crops for more granular level detail.
Will apply Bai Perron (2003) technique to dynamicallyfind break points for individual crops.
Outlook
Based on break-dates, one can build further hypothesesas to what might have caused those breaks.It would be interesting to see whether the sub-periods areanything of the kind Ramesh Chand (2012) obtains forAgriculture GDP growth rate.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Appendix
For FurtherReading
References I
R. Chand.Temporal and Spatial Variations in Agricultural Growthand Its Determinants.Economic and Political Weekly, vol XLVII No.s 2627:55–64, 2012.
Jushan Bai and Pierre PerronComputation and Analysis of Multiple Structural ChangeModels.Journal of Applied Econometrics, 18:1–22, 2003.
Madhusudan Ghosh.Structural Breaks and Performance in Indian Agriculture.Indian Journal of Agricultural Economics, 65(1):1–21,2010.
A Search forStructuralBreaks inAgricultureEconomysince
Independence
AnirudhJayaraman
Appendix
For FurtherReading
References II
Zeileis et al.strucchange: An R Package for Testing for StructuralChange in Linear Regression Models.CRAN Project, 2005.
Oehmke and Schimmelpfenning.Quantifying Structural Change in US Agriculture: TheCase of Research and Productivity.Journal of Productivity Analysis, 21:297–315, 2010.
