Title: BUYING FERTILIZER IN KENYA: WHAT ARE THE KEY DETERMINANTS
 1BUYING FERTILIZER IN KENYA WHAT ARE THE KEY 
DETERMINANTS?
- Edward Olale 
- PhD Student 
- 13 September 2007
2Acknowledgments 
- This is a product of a term paper for Advanced 
 Agricultural Marketing Course by Dr. John
 Cranfield
- I acknowledge Dr. John Cranfield, Dr. Alfons 
 Weersink, Dr. Oliver Masakure and fellow
 classmates Hina Nazli and Henry Anim-Somuah for
 their constructive comments towards the
 development of this paper
3Summary
- This study develops an analytical framework that 
 simultaneously incorporates income
 diversification, transaction costs and production
 risk in farmer fertilizer market participation
 decisions
- The framework is then tested in analyzing the 
 probability and intensity of buying fertilizer in
 Kenya, at farm level
4Outline
- Introduction 
- Theoretical Framework 
- Empirical Framework 
- Data 
- Results 
- Model Tests 
- Conclusion
5Introduction
- Improved market access is necessary for poverty 
 reduction in Kenya and other developing countries
- More attention has been given to output markets 
 than input markets
- Specifically, better access to fertilizer can 
- increase soil fertility and productivity 
- save labour 
- Fertilizer consumption levels have been low in 
 Kenya and other SSA countries (9 kg of
 nutrients/ha compared to gt70kg/ha in Latin
 America and Asia)
6Research Problem
- Joint influence of income diversification, 
 transaction costs and production risk on input
 market participation has been ignored by past
 studies
- Research on the influence of these factors on 
 fertilizer market participation is scanty
- This study aims at 
- developing an analytical framework of farmer 
 participation in fertilizer markets that
 incorporates all these factors income
 diversification, transaction costs and production
 risk
- empirically testing their influence on farmer 
 participation in fertilizer markets
7Theoretical Framework Diagram
Utility
Feed-back effect
Farmer Income
Fertilizer market participation
Input prices
Output prices
Transaction costs
Prodn risk
Farm hhs xtics
Income diversification 
 8Theoretical Framework Assumptions
- Transaction costs in the fertilizer market 
- Farmer is risk neutral 
- Possibility of production risk, but no price risk 
 
- Output is produced for sale 
- Farmer can participate in off-farm employment 
- Family labour and hired labour are perfect 
 substitutes-one wage rate (w)
- With these assumptions, the objective of the 
 farmer is to maximize expected income
9Theoretical Framework Model
- The farmers objective to maximize expected income 
 can be written as
-  Where, 
-  M is expected income 
-  is expected farm income or profit 
-  TC is transaction costs in the fertilizer 
 market
-  NFI is off-farm income 
- Transaction costs are either proportional (PTC) 
 or fixed (FTC)
10Theoretical Framework Model
- Expanding the expected income equation yields 
-  
-  
-  
-  Where, 
-  is output price 
-  q is expected output 
-  is the price of fertilizer 
-  k is fixed expenditure on other inputs 
-  is per unit proportional transaction 
 cost
-  x is fertilizer amount 
-  is family labour available for work 
-  is the labour requirement in the farm 
11Theoretical Framework Model
- The production function is specified as 
-  
-  
-  
-  Where, 
-  is the probability of no crop 
 loss and by extension
-  is the probability of crop loss 
 
-  represents farm household 
 characteristics
- The above function is substituted into the 
 expected income (M) equation
-  
12Theoretical Framework Model
- If M with fertilizer purchase gt M without 
 fertilizer purchase, then the farmer decides to
 buy fertilizer and maximizes the expected income
 equation to yield
-  
-  
-  with income 
 diversification
-  is labour 
 supply off-farm
13Theoretical Framework Hypotheses
- Comparative statics suggest that fertilizer 
 demand is
- positively influenced by output price 
- negatively influenced by fertilizer price 
- negatively influenced by per-unit proportional 
 transaction cost
- positively influenced by income diversification 
- Test for the influence of production risk 
 (probability of no crop loss) is inconclusive
- The above hypotheses are tested empirically
14Empirical Framework
- Due to data limitations, not all the derived 
 input demand equations can be estimated
- Only the derived fertilizer demand function is 
 estimated
15Empirical Framework
- Prob./intensity of fertilizer purchase 
-  F(input prices, output prices, farm household 
 characteristics, transaction costs, production
 risk, income diversification)-linear
- Specifically, 17 variables included in the model 
 were
- Prices fertilizer price perception, value of 
 crop products
- Farm household characteristics age, gender, 
 family size, crop farm size and access to
 production credit
- Transaction costs education, distance to the 
 nearest fertilizer market, agricultural extension
 and agricultural group membership
- Production risk use of drought resistant 
 varieties, access to permanent water source and
 agro-climatic zone
- Income diversification predicted wage rate 
 off-farm, predicted value of livestock and number
 of crops grown
16Empirical Framework
- Heckmans two step procedure, is used to obtain 
 predicted off-farm wage rate and value of
 livestock- since wage rate and value of livestock
 are endogenously determined
- Age, age squared, education and inverse mills 
 ratio are used to obtain predicted off-farm wage
 rate
- The same variables in the wage equation, in 
 addition to family size and value of farm
 implements are used to obtain predicted value of
 livestock
- Probit and Tobit models for probability and 
 intensity respectively
17Data
- Generated using a semi-structured questionnaire 
 administered to 228 farmers in semi-arid areas of
 Eastern Kenya
- GIS random sampling procedure was used in a 
 catchment area covering three districts
- Questions were asked on farm household 
 characteristics farm enterprise(s) soil
 fertility management technologies and marketing
 and institutional support
18Results 
Significant factors 
 19Model Tests
- Likelihood ratio tests showed that, all the 17 
 explanatory variables were jointly able to
 explain both probability and intensity of buying
 fertilizer
- Specifically, inclusion of both transaction costs 
 and production risk improved the explanatory
 power of both models
- Inclusion of income diversification only improved 
 the explanatory power of the probability model
20Conclusion 
- Income diversification positively influence 
 fertilizer market participation this may explain
 why use of labour saving inputs increase with
 more off-farm employment opportunities
- Transaction costs and production risk negatively 
 influence fertilizer market participation
- The three factors improve the explanatory power 
 of the market participation models except for
 inclusion of income diversification in the
 intensity model
- Inclusion of all the three factors is therefore 
 recommended in future agricultural input market
 participation studies
21THANK YOU
I WELCOME QUESTIONS AND COMMENTS