1. The Index and Payment Solutions of Typhoon Index Insurance for Rubber Trees in Hainan Province of China
Xinli Liu1, Tao Ye2, Jing Dong1 , Miluo Yi2, Shuyi Li1
1: Peking University, Beijing, China
2: Beijing Normal University, Beijing, China

2. The advantage of index insurance
Effective control of moral hazards and adverse selection
Encouraging policy holders to prevent or reduce loss
Reducing premium loadings, etc.
The disadvantage of index insurance
Basic risk

3. The Research Framework

4. 1. The Research Framework
1.1 Index Selection
Creating index indicators
using hazard parameters offered by sub-project one, together with data on hazard-formative environments and hazard-bearing bodies
Establishing vulnerability model
used index indicators separately and historical loss data to establish rubber tree vulnerability model, as the index–loss relationship, such as the relationship of wind speed and the loss ratio of tapped rubber trees.

5. 1. The Research Framework
1.2 Payment Solution Design
Payment scheme for single typhoon event
the initial and terminal condition for payment
determining the functional relationship between the index indicator and payment
Payment scheme for multi-typhoon events
how to accumulate the payment and maximum payment
Designing several index insurance payment schemes to insurance company for reference

6. 2. Index selection 2.1 Data 2.1.1 Data on historical loss
province-scale, county-scale, farm-scale, and production-team-scale

7. The length of typhoon wind field indicator time series
Typhoon No.
7220
0312
0518
0907
0919
1002
Start date
1972/11/2
2003/8/15
2005/9/19
2009/7/31
2009/10/8
2010/7/11
Starting time
14:00
20:00
8:00
End date
1972/11/10
2003/8/26
2005/9/27
2009/8/9
2009/10/14
2010/7/18
Ending time
Interval
10min
Duration
11880min
16200min
12960min
8640min
9360min
Damage ratio type
72*12

8. Demage ratio typies
two types of trees, that are tapped and untapped
five types of loss status, that are lodged, half-lodged, trunk broken>2m, trunk broken<2m, and all branches broken

9. 2.1.2 Data on hazard intensity Original data (per 1 km grid)
maximum Average Wind Speed (10 minute)
maximum Peak Gust Wind Speed (3 second)
wind direction
Data preprocessing
on dimension of time
on dimension of spatial

10. Derived Data Variable Description Type of variables
Maximum Average Wind Speed 1
The maximum value of Maximum Average Wind Speed, namely the maximum value of Maximum Average Wind Speed among grids within the boundary of each farm
Continuous
Maximum Average Wind Speed 2
The average value of Maximum Average Wind Speed, namely the average value of Maximum Average Wind Speed among grids within the boundary of each farm
Maximum Peak Gust Wind Speed 1
The maximum value of Maximum Peak Gust Wind Speed, namely the maximum value of Maximum Peak Gust Wind Speed among grids within the boundary of each farm
Maximum Peak Gust Wind Speed 2
The average value of Maximum Peak Gust Wind Speed, namely the average value of Maximum Peak Gust Wind Speed among grids within the boundary of each farm
Change in Wind Direction
The difference in the average value of Wind Direction in an interval of 10 minutes

11. Alternative index No. Index Description 1
The maximum value of Maximum Average Wind Speed 1
The maximum value of Maximum Average Wind Speed 1 time series within the boundary of each farm 2
The maximum value of Maximum Average Wind Speed 2
The maximum value of Maximum Average Wind Speed 2 time series within the boundary of each farm 3
The maximum value of Maximum Peak Gust Wind Speed 1
The maximum value of Maximum Peak Gust Wind Speed 1 time series within the boundary of each farm 4
The maximum value of Maximum Peak Gust Wind Speed 2
The maximum value of Maximum Peak Gust Wind Speed 2 time series within the boundary of each farm 5
The average value of Maximum Average Wind Speed 1
The average value of Maximum Average Wind Speed 1 time series within the boundary of each farm 6
The average value of Maximum Average Wind Speed 2
The average value of Maximum Average Wind Speed 2 time series within the boundary of each farm 7
The average value of Maximum Peak Gust Wind Speed 1
The average value of Maximum Peak Gust Wind Speed 1 time series within the boundary of each farm 8
The average value of Maximum Peak Gust Wind Speed 2
The average value of Maximum Peak Gust Wind Speed 2 time series within the boundary of each farm 9
The minimum value of Maximum Average Wind Speed 1
The minimum value of Maximum Average Wind Speed 1 time series within the boundary of each farm 10
The minimum value of Maximum Average Wind Speed 2
The minimum value of Maximum Average Wind Speed 2 time series within the boundary of each farm

12. No.
Index
Description 11
The minimum value of Maximum Peak Gust Wind Speed 1
The minimum value of Maximum Peak Gust Wind Speed 1 time series within the boundary of each farm 12
The minimum value of Maximum Peak Gust Wind Speed 2
The minimum value of Maximum Peak Gust Wind Speed 2 time series within the boundary of each farm 13
The volatility of Maximum Average Wind Speed 1
The standard deviation of Maximum Average Wind Speed 1 time series within the boundary of each farm 14
The volatility of Maximum Average Wind Speed 2
The standard deviation of Maximum Average Wind Speed 2 time series within the boundary of each farm 15
The volatility of Maximum Peak Gust Wind Speed 1
The standard deviation of Maximum Peak Gust Wind Speed 1 time series within the boundary of each farm 16
The volatility of Maximum Peak Gust Wind Speed 2
The standard deviation of Maximum Peak Gust Wind Speed 2 time series within the boundary of each farm 17
The maximum value of change in Wind Direction
The maximum value of the time series of change in Wind Direction 18
The average value of change in Wind Direction
The average value of the time series of change in Wind Direction 19
The minimum value of change in Wind Direction
The minimum value of the time series of change in Wind Direction 20
The volatility of change in Wind Direction
The standard deviation of the time series of change in Wind Direction

13. 2.1.3 Data on hazard-formative environments
Interpolation of precipitation before and during typhoon landing based on observations from standard weather stations
Indicator
Description
Duration
Duration of typhoon
The accumulative precipitation before typhoon landing
The accumulative 7-day precipitation before typhoon landing
The average precipitation before typhoon landing
The average 7-day precipitation before typhoon landing
The accumulative precipitation during the typhoon
The accumulative precipitation during the typhoon
The average precipitation during the typhoon
The average precipitation during the typhoon

14. The length of precipitation indicator before and during each typhoon
Typhoon No.
7220
0312
0518
0907
0919
1002
Start Date
1972/10/27
2003/8/12
2005/9/12
2009/7/24
2009/10/1
2010/7/4
Ending Date
1972/11/10
2003/8/21
2005/9/27
2009/8/9
2009/10/14
2010/7/18
Duration
15d
10d
16d
17d
Data Size
15*5
10*5
16*5
17*5

15. gradient and slope data derivated from DEM(Digital Elevation Model)
Summary of DEM-based indicators
Indicator
Description
Elevation 1
1=the standard deviation of elevation<=28.78; 0=others
Elevation 2
1=54.4>=the standard deviation of elevation n>28.78; 0=others
Elevation 3
1=84.14>= the standard deviation of elevation>54.4; 0=others
Elevation 4
1=107.64>=std of farm elevation>84.14; 0=others
Elevation 5
1=the standard deviation of elevation>107.64; 0=others

16. 2.2 Methodology Based on original variables
linear regression based on OLS
Logit regression based on MLE
Based on compositive variables
principal component regression

17. 2.3 the results Based on original variables
linear regression based on OLS
Logit regression based on MLE
Based on compositive variables
principal component regression

18. linear regression based on OLS
2.3.1 Linear and Non-linear Regression Model without precipitation indicators
linear regression based on OLS
Estimation results of comprehensive loss ratio for tapped trees after model selection

19. Estimated standard error T-value P-value Significa nce level
Variable
Coefficient
Estimated standard error
T-value
P-value
Significa nce level
Intercept
1.831 .
The maximum value of Maximum Average Wind Speed 1
3.471
***
The maximum value of Maximum Peak Gust Wind Speed 2
4.174
6.53e-05
The average value of Maximum Average Wind Speed 2
-8.934
2.68e-14
The minimum value of Maximum Average Wind Speed 2
10.909
<2e-16
The volatility of Maximum Average Wind Speed 2
4.518
1.76e-05
The volatility of Maximum Peak Gust Wind Speed 1
-6.110
2.07e-08
The maximum value of change in Wind Direction
-2.342 *
Duration
-3.527
R2:
Adjusted R2:
F-statistic: 80.88; Degrees of freedom: (8,97)
P-value: < 2.2e-16
Significance level: 0 “***”, “**”, 0.01 “*”, 0.05 “.”

20. for untapped trees Variable Coefficient Estimated standard error
T-value
P-value
Significa nce level
Intercept
2.341 *
The maximum value of Maximum Peak Gust Wind Speed 1
2.108
The average value of Maximum Average Wind Speed 2
3.250 **
The average value of Maximum Peak Gust Wind Speed 2
-4.028
***
The minimum value of Maximum Peak Gust Wind Speed 2
7.340
2.6e-10
The volatility of Maximum Average Wind Speed 2
-2.795
The volatility of Maximum Peak Gust Wind Speed 2
2.775
The maximum value of change in Wind Direction
-2.766
The average value of change in Wind Direction
-2.713
The volatility of change in Wind Direction
3.204
Duration
-2.509
R2:
Adjusted R2:
F-statistic: 18.57; Degrees of freedom: (10,72)
P-value: 2.964e-16

21. Logit Regression Model based on MLE
Estimation results of comprehensive loss ratio for tapped trees after model selection

22. Estimated standard error T-value P-value Significance level
Variable
Coefficient
Estimated standard error
T-value
P-value
Significance level
Intercept
-5.413
1.930
-2.805 **
The average value of Maximum Peak Gust Wind Speed 2
-4.802
2.351
-2.043 *
The minimum value of Maximum Average Wind Speed 2
69.497
1.965
The volatility of Maximum Peak Gust Wind Speed 2
2.184
0.775
2.819
AIC:
Significance level: 0 “***”, “**”, 0.01 “*”, 0.05 “.”

23. for untapped trees Variable Coefficient Estimated standard error
T-value
P-value
Significance level
Intercept
2.1553
-1.825
0.0679 .
The average value of Maximum Peak Gust Wind Speed 2
3.0454
-1.848
0.0646
The minimum value of Maximum Average Wind Speed 2
1.867
0.0619
The volatility of Maximum Peak Gust Wind Speed 2
2.1344
0.9843
2.168
0.0301 *
AIC: 60.08

24. linear regression based on OLS
2.3.2 Linear and Non-linear Regression Model with precipitation indicators
linear regression based on OLS
Estimation results of comprehensive loss ratio for tapped trees after model selection

25. Variable
Coefficient
Estimated standard error
T-value
P-value
Significa nce level
Intercept
4.431e-01
1.755e-01
2.525 *
The maximum value of Maximum Peak Gust Wind Speed 2
2.667e-02
4.916e-03
5.425
4.49e-07
***
The average value of Maximum Average Wind Speed 2
-8.661e-01
1.328e-01
-6.521
3.47e-09
The minimum value of Maximum Average Wind Speed 1
7.389e+00
2.204e+00
3.353 **
The minimum value of Maximum Average Wind Speed 2
1.607e+01
3.694e+00
4.350
3.45e-05
The minimum value of Maximum Peak Gust Wind Speed 1
-3.052e+00
7.552e-01
-4.041
The volatility of Maximum Average Wind Speed 2
4.159e-01
8.632e-02
4.818
5.55e-06
The volatility of Maximum Peak Gust Wind Speed 1
-1.291e-01
2.772e-02
-4.657
1.05e-05
The average precipitation before typhoon landing
-1.454e-03
5.791e-04
-2.510
The accumulative precipitation during the typhoon
2.477e-07
9.794e-08
2.529
Duration
-5.465e-02
1.252e-02
-4.365
3.26e-05
Elevation 3
7.317e-02
2.687e-02
2.724
R2:
Adjusted R2:
F-statistic: 62.39; Degrees of freedom: (11,94)
P-value: < 2.2e-16
Significance level: 0 “***”, “**”, 0.01 “*”, 0.05 “.”

26. for untapped trees Variable Coefficient Estimated standard error
T-value
P-value
Significan ce level
Intercept
2.341 *
The maximum value of Maximum Peak Gust Wind Speed 1
2.108
The average value of Maximum Average Wind Speed 2
3.250 **
The average value of Maximum Peak Gust Wind Speed 2
-4.028
***
The minimum value of Maximum Peak Gust Wind Speed 2
7.340
2.6e-10
The volatility of Maximum Average Wind Speed 2
-2.795
The volatility of Maximum Peak Gust Wind Speed 2
2.775
The maximum value of change in Wind Direction
-2.766
The average value of change in Wind Direction
-2.713
The volatility of change in Wind Direction
3.204
Duration
-2.509
R2:
Adjusted R2:
F-statistic: 18.57; Degrees of freedom: (10,72)
P-value: 2.964e-16

27. Logit Regression Model based on MLE
Estimation results of comprehensive loss ratio for tapped trees after model selection

28. Estimated standard error T-value P-value Significanc e level
Variable
Coefficient
Estimated standard error
T-value
P-value
Significanc e level
Intercept
-2.642 **
The maximum value of Maximum Average Wind Speed 2
3.780
***
The average value of Maximum Peak Gust Wind Speed 2
-1.946 .
The minimum value of Maximum Peak Gust Wind Speed 2
2.193 *
AIC:
Significance level: 0 “***”, “**”, 0.01 “*”, 0.05 “.”

29. for untapped trees Variable Coefficient Estimated standard error
T-value
P-value
Significance level
Intercept
2.1553
-1.825
0.0679 .
The average value of Maximum Peak Gust Wind Speed 2
3.0454
-1.848
0.0646
The minimum value of Maximum Average Wind Speed 2
1.867
0.0619
The volatility of Maximum Peak Gust Wind Speed 2
2.1344
0.9843
2.168
0.0301 *
AIC: 60.08

30. 2.3.3 Principal Component Regression without precipitation indicators
Factor loading of principal components without precipitation indicators

31. PC 1
PC 2
The maximum value of Maximum Average Wind Speed 1
0.01
-0.43
The maximum value of Maximum Average Wind Speed 2
-0.30
The maximum value of Maximum Peak Gust Wind Speed 1
0.02
-0.64
The maximum value of Maximum Peak Gust Wind Speed 2
-0.51
The average value of Maximum Average Wind Speed 1
-0.05
The average value of Maximum Average Wind Speed 2
-0.03
The average value of Maximum Peak Gust Wind Speed 1
-0.07
The average value of Maximum Peak Gust Wind Speed 2
The minimum value of Maximum Average Wind Speed 1
0.00
The minimum value of Maximum Average Wind Speed 2
The minimum value of Maximum Peak Gust Wind Speed 1
The minimum value of Maximum Peak Gust Wind Speed 2
The volatility of Maximum Average Wind Speed 1
-0.09
The volatility of Maximum Average Wind Speed 2
-0.06
The volatility of Maximum Peak Gust Wind Speed 1
-0.13
The volatility of Maximum Peak Gust Wind Speed 2
-0.10
The maximum value of change in Wind Direction
1.00
0.04
The average value of change in Wind Direction
The minimum value of change in Wind Direction
The volatility of change in Wind Direction
0.05
Duration
-0.04
0.08
Elevation 1
Elevation 2
Elevation 3
Elevation 4

32. Estimation results of comprehensive loss ratio for tapped trees
Variable
Coefficient
Estimated standard error
T-value
P-value
Significance level
Intercept
6.482
3.18e-09
***
PC 1
-2.078
0.0402 *
PC 2
<2e-16
0.5957
Adjusted R2:
F-statistic: 75.87; Degrees of freedom: (2,103)
P-value : < 2.2e-16

33. Estimation results of comprehensive loss ratio for untapped trees
Variable
Coefficient
Estimated standard error
T-value
P-value
Significance level
Intercept
4.050
***
PC 1
-1.080
PC 2
-6.985
7.57e-10
R2:
Adjusted R2: 0.399
F-statistic: 28.22; Degrees of freedom: (2,80)
P-value: < 5.315e-10

34. 2.3.4 Principal Component Regression with precipitation indicators
Factor loading of principal components without precipitation indicators

35. PC 1
PC 2
PC 3
The maximum value of Maximum Average Wind Speed 1
0.00
-0.02
The maximum value of Maximum Average Wind Speed 2
The maximum value of Maximum Peak Gust Wind Speed 1
-0.04
The maximum value of Maximum Peak Gust Wind Speed 2
The average value of Maximum Average Wind Speed 1
The average value of Maximum Average Wind Speed 2
The average value of Maximum Peak Gust Wind Speed 1
The average value of Maximum Peak Gust Wind Speed 2
The minimum value of Maximum Average Wind Speed 1
The minimum value of Maximum Average Wind Speed 2
The minimum value of Maximum Peak Gust Wind Speed 1
The minimum value of Maximum Peak Gust Wind Speed 2
The volatility of Maximum Average Wind Speed 1
The volatility of Maximum Average Wind Speed 2
The volatility of Maximum Peak Gust Wind Speed 1
The volatility of Maximum Peak Gust Wind Speed 2
The maximum value of change in Wind Direction
0.12
The average value of change in Wind Direction
The minimum value of change in Wind Direction
The volatility of change in Wind Direction
0.01
The accumulative precipitation before typhoon landing
-1.00
The average precipitation before typhoon landing
-0.38
The accumulative precipitation during the typhoon
-0.01
The average precipitation during the typhoon
-0.92
Duration
Elevation 1
Elevation 2
Elevation 3
Elevation 4

36. Estimation results of comprehensive loss ratio for tapped trees
Variable
Coefficient
Estimated standard error
T-value
P-value
Significance level
Intercept
1.078e-01
3.397e-02
3.173
0.0020 **
PC 1
-9.478e-04
4.729e-04
-2.004
0.0477 *
PC 2
-1.015e-02
1.092e-03
-9.298
3.15e-15
***
The accumulative precipitation before typhoon landing
2.044e-07
2.193e-07
0.932
0.3535
The accumulative precipitation during the typhoon
2.056e-08
1.245e-07
0.165
0.8692
R2:
Adjusted R2:
F-statistic: 37.94; Degrees of freedom: (4,101)
P-value: < 2.2e-16

37. Estimation results of comprehensive loss ratio for untapped trees
Variable
Coefficient
Estimated standard error
T-value
P-value
Significance level
Intercept
-2.758e-03
4.064e-02
-0.068
0.9461
PC 1
-7.334e-04
5.457e-04
-1.344
0.1829
PC 2
-6.504e-03
1.188e-03
-5.475
5.14e-07
***
The accumulative precipitation before typhoon landing
1.649e-07
2.503e-07
0.659
0.5120
The accumulative precipitation during the typhoon
4.265e-07
1.925e-07
2.216
0.0296 *
R2:
Adjusted R2: 0.456
F-statistic: 18.19; Degrees of freedom: (4,78)
P-value: 1.371e-10

38. 2.4 the analysis
Hazard intensity indicator -- Wind Speed and Wind Direction
Explanatory power
Friendliness
Auxiliary indicator of hazard-formative environment -- Precipitation
Resolution ratio
Maximum Peak Gust (3s) Wind Speed (m/s)
the average value of Maximum Peak Gust (3s) Wind Speed (m/s) for 1 kilometer-scaled grid within the boundary of each farm

39. 3. Relationship between the index and loss ratio
when the index indicator is relatively low
y=c/(1+exp(ax+b)
Type of loss
Smooth Interval
Parameter
Lower Limit of Maximum Peak Gust (3s) Wind Speed (m/s)
Upper Limit of Maximum Peak Gust (3s) Wind Speed (m/s) a b c
Tapped rubber trees
Lodged
10.8
26.45
6.67
9.604
Half-lodged
7.417
Trunk broken<2m
13.021
Trunk broken>2m
22.405
All branches broken
30.600
Untapped rubber trees
13.9
4.63
7.194
22.6
5.419
7.552
30.55
14.792

40. Extrapolation interval
when the index indicator is relatively high
y=c/(1+exp(ax+b)
Type of loss
Extrapolation interval
Parameter
Lower Limit of Maximum Peak Gust (3s) Wind Speed (m/s)
Upper Limit of Maximum Peak Gust (3s) Wind Speed (m/s) a b c
Tapped rubber trees
Lodged
43.9 60
-0.221
8.856
24.799
Half-lodged
-0.139
5.264
7.234
Trunk broken<2m
-0.182
7.139
23.320
Trunk broken>2m
-0.188
7.393
24.272
All branches broken
-0.151
5.759
20.374
Untapped rubber trees
-0.168
7.177
17.778
-0.103
4.321
13.322
-0.185
7.944
24.097
-0.220
9.463
17.287
-0.216
9.293
27.515

41. Median of Wind Speed range
The average loss ratio for the median of each Maximum Peak Gust (3s) Wind Speed range
Tapped rubber trees
Wind Speed scale
Wind Speed range
Median of Wind Speed range
(m/s)
Lodged
Half- lodged
Trunk broken< 2m
Trunk broken> 2m
All branche s broken
Average (%) 10
24.5 ~ 28.4
26.45
0.96
0.74
1.31
2.25
3.07 11
28.5 ~ 32.6
30.55
3.95
2.17
4.03
4.86
6.05 12
32.7 ~ 36.9
34.8
6.13
2.97
8.18
6.24
7.33 13
37.0 ~ 41.4
39.2
8.60
3.46
12.68
11.90
10.85 14
41.5 ~ 46.1
43.8
17.28
5.00
16.25
16.91
14.20

42. Median of Wind Speed range
Untapped rubber trees
Wind Speed scale
Wind Speed range
Median of Wind Speed range
(m/s)
Lodged
Half- lodged
Trunk broken<2 m
Trunk broken>2 m
All branches broken
Average (%) 7
13.9 ~ 17.1
15.5 /
0.55 8
17.2 ~ 20.7
18.95
0.54 9
20.8 ~ 24.4
22.6
0.77
0.42 10
24.5 ~ 28.4
26.45
0.78
1.37
1.01
0.82 11
28.5 ~ 32.6
30.55
2.33
4.00
2.16
2.09
2.25 12
32.7 ~ 36.9
34.8
3.91
5.16
2.14
3.61 13
37.0 ~ 41.4
39.2
5.00
6.12
8.11
3.79
4.84 14
41.5 ~ 46.1
43.8
9.60
7.22
13.06
9.37
14.91

43. Extrapolation interval
when the index indicator is relatively high
y=c/(1+exp(ax+b)
Type of loss
Extrapolation interval
Parameter
Lower Limit of Maximum Peak Gust (3s) Wind Speed (m/s)
Upper Limit of Maximum Peak Gust (3s) Wind Speed (m/s) a b c
Tapped rubber trees
Lodged
43.9 60
-0.221
8.856
24.799
Half-lodged
-0.139
5.264
7.234
Trunk broken<2m
-0.182
7.139
23.320
Trunk broken>2m
-0.188
7.393
24.272
All branches broken
-0.151
5.759
20.374
Untapped rubber trees
-0.168
7.177
17.778
-0.103
4.321
13.322
-0.185
7.944
24.097
-0.220
9.463
17.287
-0.216
9.293
27.515

44. 4. Payment Solution The payment process for single typhoon event
Typhoon index insurance being triggered
Calculation and publication of the insurance index
Calculation of comprehensive loss ratio
Calculation of comprehensive loss
Calculation of the amount of payment
Claim settlement

45. The physical loss ratio corresponding to the insurance index
The calculation of physical loss ratio
The average loss ratio of each Wind Speed range in Scheme C is derived from the simulated typhoon event set (with typhoons and 1000 event years) provided by Sub-project One
No. of Scheme
The corresponding relationship between the insurance index and the physical loss ratio A
The physical loss ratio corresponding to the insurance index B
The physical loss ratio corresponding to the lower limit of the Wind Speed range which the insurance index falls into C
The average loss ratio of the Wind Speed range which the insurance index falls into

46. The payment ratio for each rubber tree
The calculation of comprehensive loss ratio
The payment ratio corresponding to each loss type
Comprehensive loss ratio for tapped/untapped rubber trees = physical loss ratio for lodged trees * 100% + physical loss ratio for half-lodged trees * 30% + physical loss ratio for trees with trunk broken ≤ 2m * 100% + physical loss ratio for trees with trunk broken > 2m * 30% + physical loss ratio for trees with all branches broken * 30%.
Type of loss
The payment ratio for each rubber tree
Lodged
100%
Half-lodged
30%
Trunk broken≤2m
Trunk broken>2m
All branches broken

47. Wind Speed Threshold and Upper Limit of Payment
Nine Payment Solutions
Threshold wind speed
Corresponding loss ratio
17.2m/s
(lower limit of Beaufort scale 8)
20.8m/s
(lower limit of Beaufort scale 9)
24.5m/s
(lower limit of Beaufort scale 10)
The index corresponding, based on the vulnerability AI
AII
AIII
The lower limit of the range which the index within corresponding BI
BII
BIII
The average of the range which the index within CI
CII
CIII

48. The payment process for multi-typhoons
Since Hainan Province is often affected by multiple typhoons within a single year, we need to adopt a dynamic method to determine the number of effective rubber trees.
The number of effective rubber trees for the first typhoon of the year is subject to the number specified in the insurance policy.
The number of effective rubber trees for the second typhoon of the year is the original number minus the number of rubber trees which are affected during the first typhoon:
In the above equation, is the index calculated and published during the first typhoon, is the comprehensive loss ratio for the first typhoon.
The number of effective rubber trees for the third typhoon of the year is the number of effective rubber trees for the second typhoon minus the number of rubber trees which are affected during the second typhoon:
And so on.

49. Thanks