CAPRI
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capri:concept:refrun [2011/04/11 11:31]
131.220.212.14 created
capri:concept:refrun [2014/06/03 16:15]
mihalyh
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 +<​HTML>​
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 +         <​div class=rightwindow>​
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 +      <​H2>​Reference run</​H2>​
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 +      <​H3>​Overview</​H3>​
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 +      <TABLE padding="​20px"><​TR><​TD>​
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 +      <​P>​The reference run or baseline serves as a reference point for ex-ante impact analysis
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 +      with CAPRI. It reflects the most probable development in agricultural markets
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 +      from global to regional scale for 8-10 year time horizon, at the current legislation.
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 +      It integrates agricultural market projections from other institutions as OECD, FAPRI, FAO and DG-AGRI.
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 +      Unique for CAPRI is the regional resolution below the national level for EU27 at the level of
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 +      NUTS 2 regions and farm types inside NUTS 2 region, and the Bayesian methodology applied.</​P>​
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 +      <​P>​The <A HREF="​supply.htm">​supply</​A>​ and <A HREF="​market.htm">​market</​A>​ module
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 +      are calibrated to results of the reference run.</​P>​
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 +      <P>In opposite to many other reference run approaches, CAPRI employs a Bayesian estimation
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 +      framework to define a mutually consistent set of projection values for activity levels,
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 +      yields, production, feed and processing demand, human consumption,​ trade etc. Basically,
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 +      all major equations from the supply and market modules are defined as in an optimization
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 +      framework which maximizes the joint posterior density for given a priori distribution
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 +      of the different elements. The a priori distribution is whereever possible derived to from exogenous forecasts or expert information.</​P>​
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 +      </TD>
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 +      <​TD><​P><​a href="​images\refrun.gif"><​img style="​text-decoration:​ none;​border:​ none;color: white" src="​images\refrun.gif"​ width="​500px"/></​a></​P>​
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 +      </TD>
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 +      </TR>
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 +      </​TABLE>​
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 +      <​H3>​Methodology</​H3>​
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 +      <TABLE padding="​10 px"><​TR>​
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 +      <​TD><​P><​a href="​images\support.jpg"><​img style="​text-decoration:​ none;​border:​ none;color: white;​padding:​20px;​margin:​20px;"​ src="​images\support.jpg"​ width="​500px"/></​a></​P>​
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 +      </TD>
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 +      <TD>
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 +      <​P>​The a priori distributions are derived from two different sources. For all elements,
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 +      long term trends are projected. Using "no change"​ as the zero hypothesis, a weighted average
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 +      between the base year value and the trend estimate is calculated, using R squared
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 +      as weight for the trend estimate. The
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 +      resulting estimates along with the estimation error of the trend deliver a priori distributions
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 +      for all items in the estimation framework.</​P>​
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 +
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 +      <P>In a first step, the estimation is solved for these trend support, indepedently for each country. Afterwards, results are aggregated to
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 +      EU. The projections of other instutions are then added, and replace where available the supports based on trends.
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 +      If the projections are only reporting values for the EU and not for individual countries,
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 +      the country results from the first steps are used to distributed the EU estimate. The standard errors for the there projections,​
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 +      especially for those provided by DG-AGRI, is set rather narrow, ensuring that the values are recovered as long as they do not violate
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 +      the consistency restrictions.</​P>​
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 +     <​P>​The estimation is then repeated in a second step based on the updated supports. The country results are then taken is given, and broken
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 +     down in a similar framework to NUTS 2 level, and from there to farm type groups.</​P>​
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 +
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 +      </TD>
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 +      </TR>
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 +      </​TABLE>​
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 +     <​H3>​Quality control</​H3>​
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 +     <​P>​Due to the NUTS 2 resolution with its 280 regions, and the high number of activities, outputs and inputs covered by the CAPRI modelling
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 +     ​system,​ the references comprises several Mio numbers. Therefore, aggregates over activities (single cereals aggregated to all cereals)
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 +     and products, and over countries to EU15, EU10 etc. are defined and reported in tables accessible via the Graphical user interface.
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 +     Those tables compare systematically the different inputs (trend estimate, policy shift, estimation results from the different steps).</​P>​
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 +
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 +     <​P>​Nevertheless,​ checking results for plausibility remains a challenge. An interested comparison of the methdology between the reference
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 +     run exercise for the OECD/FAO AGLINK-COSIMO model with an estimated input of 20 person months and the CAPRI reference run
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 +     with an estimated inputs of about 2 person months is reported by <A HREF=http://​purl.umn.edu/​44120>​Adenauer 2008</​A>​.</​P>​
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 + <​H3>​Calibration to the EC mid-term market outlook</​H3>​
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 + The CAPRI baseline is regularly calibrated to the mid-term commodity outlook of the European Commission. More on the technical and institutional aspects can be found in the following JRC reports: <br>
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 + <​I><​a HREF="​https://​ec.europa.eu/​jrc/​en/​publication/​calibrating-capri-and-esim-models"​ class="​intext">​Calibrating CAPRI to the mid-term commodity outlook of the EC</​a></​I> ​
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 +  <br>
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 + <​I><​a HREF="​http://​ipts.jrc.ec.europa.eu/​publications/​pub.cfm?​id=4879"​ class="​intext">​Background information on the baseline construction process</​a></​I> ​
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 +  ​
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 +<​H3>​More information</​H3>​
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 +<P class="​pubparagraph"><​span class="​pubAuthor">​Witzke H.P. and Adenaeuer M.</​span>:<​BR>​
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 +<​I><​a HREF="​..\docs\capri_baseline.pdf"​ class="​intext">​Capri Baseline (pdf, 13 slides)</​a></​I></​p>​
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 +<font size=1>​Last Updated:​Tuesday,​ October 28, 2008
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 +</​font>​
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 +         </​div><​!-- Ende RightWindow -->
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 +      </​div><​!-- Ende content -->
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