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

Crop Switching temperature Net Revenue ($/ha) wheat corn soybean millet

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