Project

General

Profile

Demand (16_demand)

Description

The demand module calculates the demand for all commodities that has to be fulfilled by the model. In addition, it returns some other basic information needed for demand calculations but also needed by other modules. Examples are GDP per capita values or human metabolizable energy (ME) contents.
A description of food demand scenarios that enter the model can be found in Bodirsky et al1 (in review), Bodirsky et al2 (2012) and Valin et al3 (2014).

Interfaces

Input

Name Description Unit A
$vm\_prod\_reg(i,k)$ Regional aggregated production mio. ton DM x
$vm\_dem\_feed(i,kli,kbio)$ Regional feed demand including byproducts mio ton DM x
$vm\_dem\_bioen(i,k)$ Regional bioenergy demand mio. ton DM x
$fm\_GE\_content(k)$ Gross energy content GJ per ton DM x

The last columns of the table indicate the usage in the different realizations (numbered with capital letters)

Output

Name Description Unit
$vm\_supply(i,k)$ Regional demand mio ton DM
$im\_dem\_food(t,i,k)$ Regional food demand $10^6$ ton DM
$im\_dem\_material(t,i,k)$ Regional material demand $10^6$ ton DM
$fm\_prod\_cal(i,k)$ Calibration of FBS production to ProdSTAT production [FAO - FBS] -
$fm\_human\_ME\_content(i,k)$ Calculated human metabolizable energy content [FAO - FBS] GJ per ton DM
$fm\_gdp\_pc(t\_all,i)$ GDP per capita - MER US$ 2005
$fm\_seed\_shr(i,k)$ seed share relative to production [FAO - FBS] -

Interface plot


Figure 0: Information exchange among modules

Realizations

(A) basic_AFRfix (default)

In the basic realization, demand (vm_supply) is calculated as the sum of exogenous food demand, exogenous material demand, feed demand coming from the 70_livestock module, bioenergy demand coming from the 60_bioenergy module and additional demand for seeds which is proportional to the regional production.

\begin{equation}
vm\_supply(i,k) = ic16\_dem\_food(i,k)
\\+ ic16\_dem\_material(i,k)
\\+ vm\_dem\_bioen(i,k)
\\+ vm\_prod\_reg(i,k) \cdot fm\_seed\_shr(i,k)
\\+ \sum_{kli} vm\_dem\_feed(i,kli,k)
\end{equation}

Limitations
Food demand projections enter the model as exogenous scenarios. Such an inelastic representation cannot capture impacts of i.e. bioenergy production or policies on food demand via price signals.

Definitions

Name Description Units A
$i16\_food\_ME\_shr\_new(t,i,k)$ Updated food shares (1) - x
$ic16\_dem\_food(i,k)$ Regional food demand for the actual time step $10^6$ ton DM x
$ic16\_dem\_material(i,k)$ Regional material demand for the actual time step $10^6$ ton DM x

The last columns of the table indicate the usage in the different realizations (numbered with capital letters)

Developer(s)

Isabelle Weindl, Benjamin Bodirsky, Jan Philipp Dietrich

See Also

21_trade, 60_bioenergy, 70_livestock, Mathematical Description, [[mo:Coding Etiquette]]

References

1 Bodirsky B.L., Rolinski S., Biewald A., Weindl I., Popp A., Lotze-Campen H. (in review): Global food demand scenarios for the 21st century

2 Bodirsky B.L., Popp A., Weindl I., Dietrich J.P., Rolinski S., Scheiffele L., Schmitz C., and Lotze-Campen H. (2012): N2O emissions from the global agricultural nitrogen cycle – current state and future scenarios. Biogeosciences, 9, 4169-4197 http://www.biogeosciences.net/9/4169/2012/bg-9-4169-2012.html

3 Valin H., Sands R., van der Mensbrugghe D. et al. (2014): The future of food demand: understanding differences in global economic models. Agricultural Economics 45: 51-67 http://onlinelibrary.wiley.com/doi/10.1111/agec.12089/abstract