Difference between revisions of "Improvement of MCYFS forecasts"

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|Overall || 26.59 || 36.36 || 8.50 ||  
 
|Overall || 26.59 || 36.36 || 8.50 ||  
 
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Note: Bold values indicate significant cases at the 0.05 level.
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'''Note: Bold values indicate significant cases at the 0.05 level.'''
  
 
The RMSPE in 1998-2002 for Durum wheat is smaller than the respective RMSPE of 1993-1997 in all months. The improvement in May, June and August is considered statistically significant. Moreover, the p-values of April, July and October are small. Therefore, there are very strong indications that MCYFS has improved in the forecasting of Durum wheat yield after 1998. The contents of the table are displayed in the following graph:
 
The RMSPE in 1998-2002 for Durum wheat is smaller than the respective RMSPE of 1993-1997 in all months. The improvement in May, June and August is considered statistically significant. Moreover, the p-values of April, July and October are small. Therefore, there are very strong indications that MCYFS has improved in the forecasting of Durum wheat yield after 1998. The contents of the table are displayed in the following graph:
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|Overall || 4.46 || 5.74 || 1.91 ||  
 
|Overall || 4.46 || 5.74 || 1.91 ||  
 
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|}
Note: Bold values indicate significant cases at the 0.05 level.
+
'''Note: Bold values indicate significant cases at the 0.05 level.'''
  
 
The RMSPE in 1998-2002 is smaller than the respective RMSPE of 1993-1997 in all months. The improvement in June, August and October is considered statistically significant. Moreover, the p-values of April, May and July are small. Therefore, there are very strong indications that MCYFS has improved in the forecasting of Grain maize yield after 1998.The contents of the table are presented in the following diagram:
 
The RMSPE in 1998-2002 is smaller than the respective RMSPE of 1993-1997 in all months. The improvement in June, August and October is considered statistically significant. Moreover, the p-values of April, May and July are small. Therefore, there are very strong indications that MCYFS has improved in the forecasting of Grain maize yield after 1998.The contents of the table are presented in the following diagram:
  
 
[[File:linechart_monthly_rmspe_grain_maize.jpg|Linechart of monthly RMSPEs for Grain maize]]
 
[[File:linechart_monthly_rmspe_grain_maize.jpg|Linechart of monthly RMSPEs for Grain maize]]
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RMSPEs after 1998 are definitely smaller than those before 1998. The improvement is slightly smaller in the second half of the year than in the first.
 
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The RMSPE in 1998-2002 is greater than the respective RMSPE of 1993-1997 from April until July, and smaller thereafter. No statistically significant improvement in 1998-2002 is detected. The figure below shows that RMSPEs after 1998 are greater than those before 1998 for all months up to July. The only month where RMSPEs denote improvement after 1998 is September.
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The RMSPE in 1998-2002 is greater than the respective RMSPE of 1993-1997 from April until July, and smaller thereafter. No statistically significant improvement in 1998-2002 is detected.
  
 
[[File:linechart_monthly_rmspe_rape_seed.jpg|Linechart of monthly RMSPEs for Rape seed]]
 
[[File:linechart_monthly_rmspe_rape_seed.jpg|Linechart of monthly RMSPEs for Rape seed]]
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The figure shows that RMSPEs after 1998 are greater than those before 1998 for all months up to July. The only month where RMSPEs denote improvement after 1998 is September.
 
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{|class="collapsing_table collapsible collapsed"
 
{|class="collapsing_table collapsible collapsed"
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|Overall || 5.26 || 6.80 || 2.32 ||  
 
|Overall || 5.26 || 6.80 || 2.32 ||  
 
|}
 
|}
Note: Bold values indicate significant cases at the 0.05 level.
+
'''Note: Bold values indicate significant cases at the 0.05 level.'''
  
 
The RMSPE in 1998-2002 is smaller than the respective RMSPE of 1993-1997 in all months. The improvement in August and October is considered statistically significant. Moreover, the p-values of May, June, July and September are small. Therefore, there are very strong indications that MCYFS has improved in the forecasting of Potato yield after 1998.
 
The RMSPE in 1998-2002 is smaller than the respective RMSPE of 1993-1997 in all months. The improvement in August and October is considered statistically significant. Moreover, the p-values of May, June, July and September are small. Therefore, there are very strong indications that MCYFS has improved in the forecasting of Potato yield after 1998.

Latest revision as of 10:35, 19 June 2012



The purpose of this section is to examine whether the performance of MCYFS in the period 1998-2002 improved compared to its performance in the period 1993-1997. Performance is assessed in terms of average error size and more specifically in terms of RMSPE.

Separately for each crop monthly RMSPE have been computed averaging the MCYFS errors, for the given month, during the two periods in question. Errors refer to EU-total forecasts. EU-total denotes EU12 until 1995 and EU15 from 1996 onwards.

Moreover, a Wilcoxon test on each month's absolute percentage errors is applied to test the null hypothesis (H 0) that absolute percentage errors have not improved (i.e. have not decreased) during the period 1998-2002 as opposed to the period 1993-1997. Therefore small p-values (less than 0.05 in this document) reject the null hypothesis and show improvement (reduction) of errors and hence better performance of MCYFS.