Climate Change Adaptation:
Crop Choice
Crop Choice
• As climate changes, net revenues of plants
change
– Crops move along their climate response
function
• Crop Models often assume no response
despite falling productivity
Farmer’s Switch Crops
• With warming, current crop becomes
ineffective, and farmers switch to a more
warm loving crop
• Similarly, as precipitation rises or falls, farmers
switch to new crop more suited for new
condition
African Crops vs Temperature
African Livestock vs Precipitation
How can you determine how farmers in your country will adapt?
Look at choices that they are making now in current climate.
See how these choices change depending on local climate.
Build model of crop choice.
Farmer Crop Mix
Climate
(temperature and
precipitation)
Key Assumptions
Climate is exogenous
Farmer cannot change climate at farm
Farmers doing what is in their “best interest”
Maximize their net benefits
Farmer’s crop choice is best choice given local
conditions.
Data Needed
•
•
•
•
Crop choices of each farmer
Climate and soil of each farm
Economic variables such as access to markets
Size of farm
Estimation
• Logit for single crop
• Pr=exp(BX)/(1-exp(BX))
• Multinomial logit for multiple crops
• Pr (Yi)=exp(BiXi)/[1+∑exp(BjXj)]
Hands-on Exercise
Sample: 8,000+ farmers across China
Key Questions
1) How does climate affect the choice to
grow rice?
2) How does climate affect all crop choices in
China?
Major Method(s):
1) Logit
2) Multinomial logit regression