1. Does Colony Loss Reduce Honey Yield?
Peyton Ferrier, Economic Research Service, USDA
Applied Social Science Association Meeting,
Atlanta, GA, January 5-7, 2019
Disclaimer:
The findings and conclusions in this preliminary presentation have not been formally disseminated by the U. S. Department of Agriculture and should not be construed to represent any Agency determination or policy.
This research was supported in part by the intramural research program of the U.S. Department of Agriculture, Economic Research Service.

2. Introduction Since 2000, beekeeping has experienced three big shifts:
Colony loss rates have doubled - average 28.7 percent
Honey yields fell 29.3 percent
Pollination service income rose from 11 to 41 percent between 1988 and 2016
In 2016, almonds accounted for 82 % of pollination services fees, 60% of colony rentals, and 52 % of paid pollinated acres.
Massive acreage, high fees, highly pollinator-dependent, distant for BK (only in CA), blooms in late winter, almond honey tastes bad and not sold.
Most concern over the effect of pollinator loss on ag production (Morse and Calderone, 2000; Gallai et al., 2009)

3. Source: USDA ERS Fruit and Tree Nut Yearbook (2017)
CA Almonds ( )
Real Rev Growth – 626%
Real Price – 158%
CA Almonds ( )
Acreage Growth – 96%
Production – 223%
Real Value (2017 Base)
$ Million
$7,650 Million
$5,603 Million
Real Prices (2017 Base)
$/lb
$/lb
$/lb
Source: USDA ERS Fruit and Tree Nut Yearbook (2017)
Source: USDA NASS California Almond Report (2017)

5. Source: USDA ERS Sugars and Sweeteners Yearbook (2017)
Avg U.S. Honey Yields
– 66.5 lb/col
– 81.4 lb/col
lb/col
Honey Producing Cols
1986 – 3.2 million
2000 – 2.6 million
2017 – 2.7 million
Real Honey Price
= 1.02 $/lb
= 1.83 $/lb
(2001 antidumping tariff)
= 1.26 $/lb
= 1.70 $/lb
= 2.14 $/lb
Source: USDA ERS Sugars and Sweeteners Yearbook (2017)

6. Source: USDA ERS Sugars and Sweeteners Yearbook (2017)

7. Background on Colony Loss
Causes
Abiotic – weather, poor forage/lack of nutrition, pesticide exposure, colony movement
Biotic Stressors – Varroa mite, viruses (deformed wing, etc.), Wax Moths, Small Hive Beetle, Nosema Ceranae, etc.
Movement likely facilitates the transmission of biotic stressors when colonies are concentrated in staging areas.
BK replace loss colonies primarily through splitting healthy colonies so that new colonies are smaller.
If bee populations are equals size, two small colonies produce less honey than one big one.

8. Two reasons why honey yields might fall:

9. Data
NASS Honey Production – annual BK survey of prod, colonies, yield.
4 years ( )
y – yield
size – lagged colonies
NASS Colony Loss – quarterly BK survey of colonies, losses, additions, requeenings, and stressors. Lists state locations of colonies.
10 Quarters (2015Q1-2017Q2)
loss – 2-quarter loss rate (sum of Q1 and Q2 losses/sum of Q1 and Q2 colonies)
cali – max share of colonies in California in Q1 and Q2
move – difference of average colony distance to California in Q1 and Q3
ey – expected yield
1. Find BK share of colonies in each state in 3rd quarter (honey season)
2. Multiply state shares by state average yields

10. Estimating the effect on honey yields of colony loss and almond pollination
Pooled model – data too short for BK fixed effects
Early share of colonies in CA is proxy for almond pollination
Controls for productivity BK
Size, Lagged yields, Difference model
Controls for market shocks/regional productivity shifters
Expected yields
Instrument for loss rate using IT2SLS to avoid measurement error bias (colonies appears in the denominators of both yield and loss rate)
Weighted regression - Size Interacted with Loss

11. Source: NASS Honey Product and Colony Loss Data (2014-17)

12. Source: NASS Honey Product and Colony Loss Data (2014-17)

14. Source: Author’s Calculations based on NASS Data

15. Source: Author’s Calculations based on NASS Data

16. Results
Productivity Controls (Lagged Yield, Expected Yield) are strongly significant and positive as expected.
A 10 percentage point increase in CA share decreases yield by:
0.77 pounds (or 1.46 percent) in the yield model
2.96 percent (or 1.56 pounds) in the difference model
Effect of loss dissipates with increasing size of operations.
A 1 percentage point increase in the loss rate* decreases yields by:
.362 pounds (or 0.69 percent) in the yield model
percent (or .347 pounds) in the difference model
Yield is assumed to be 52.7 pounds in calculations

17. Source: Author’s Calculations based on NASS Data

18. Implications
Overwinter loss rates of colonies is thought to have increased 15 percentage points above its historic average, a change corresponding to a 7.5 percentage point increase in our 2-quarter loss rate. This change in loss rate reduces yields by 2.7 pounds or 5.2 percent.
A 30 percent point increase in the share of colonies in California in Q1 would reduce yields by 2.32 pounds or 4.4 percent.
Collectively, elevated colony loss and movement in service of almond pollination are estimated to reduce honey yields by 9.6 percent or 33 percent of the 29.3 percent total reduction in yields.

19. Conclusions
Colony loss reduces honey yield, but the incentive of high almond fees play a large role as well.
High almond pollination service fees can reduce yields through multiple channels. Our model does not sort out the specific mechanism.
Other factors may affecting honey yield are not addressed here
Forage loss, weather, sub-lethal effects of stressors.

20. Contact Information
Peyton Ferrier Economics Research Service, USDA