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--- input_allocation [2020/02/13 11:18] – [Input allocation for young animals and the herd flow model] matsz
+++ input_allocation [2020/02/13 11:34] – [Input allocation for feed] matsz
@@ Line 130: / Line 130: @@
 \begin{equation}
-\sum_{r,fint}\bar{FEDUSE}_{r,fint}PFOD_{r,fint} = \bar{EAAP}_{OFAR,MS}+\bar{EAAP}_{GRAS,MS}
+\sum_{r,fint}\overline{FEDUSE}_{r,fint}PFOD_{r,fint} = \overline{EAAP}_{OFAR,MS}+\overline{EAAP}_{GRAS,MS}
 \end{equation}
+Secondly, the Gross Value Added of the fodder activities is defined as the difference between main revenues (from main fodder yield), other revenues, and total input costs based on the input allocation for crops described above.
+\begin{equation}
+GVAM_{r,fint} = \overline{YIELD}_{r,fint}PFOD_{r,fint}+\overline{OREV}_{r,fint}-\overline{TOIN}_{r,fint}
+\end{equation}
+Other revenues may be from the nutrient value in crop residues. Next, an HDP objective is added which penalises deviations from the a priori mode.
+The a priori mode for the prices of ‘grass’ and ‘other fodder on arable land’ are the EAAP values divided by total production volume which is by definition equal to feed use. The price of straw for feed use is expected to be at 1 % of the grass price.
+Supports for Gross Value Added per activity are centred around 150 % of the value of total inputs as allocated by the rules and algorithm described above, with wide bounds.
+Wide supports for the Gross Value Added of the fodder activities mirror the problem of finding good internal prices but also the dubious data quality both of fodder output as reported in statistics and the value attached to it in the EAA. The wide supports allow for negative Gross Value Added, which may certainly occur in certain years depending on realised yields. In order to exclude such estimation outcomes as far as possible an additional constraint is introduced:
+\begin{equation}
+GVAM_{r,fint} \ge \overline{TOIN}_{r,fint}\overline {gvafac} \text PLATZHALTER EQUATION 37
+\end{equation}
+The parameter \(gvafac\) is initialised with zero so that first a solution is tried where all activities have positive GVAs. If infeasibilities arise, the factor is stepwise increased until feasibility is achieved, to ensure that estimated fodder prices are giving the minimal number of activities with negative Gross Value Addeds.
+===Calibration of the feed allocation ===
+The allocation of feed to animal activities has been changed several times (like the fertiliser allocation). The most recent version has been developed ((This section draws upon a corresponding Star 2 deliverable and coding which are due in major parts to CAPRI expert Markus Kempen. As Markus was not involved in this documentation, he is released from any responsibility for remaining errors. A more detailed version of this section is offered as [[https://www.capri-model.org/dokuwiki/lib/exe/fetch.php?media=docu_feed_calib.pdf]].)) in the Stable Release 2 (in the following: “Star2”) project which will become also the standard version in the CAPRI trunk at the next opportunity.
+**General concept**