From global economic modelling to household level analyses of food security

and sustainability:

how big is the gap and can we bridge it?

Mark van Wijk

Policy and decision makers have to make difficult choices to

address issues around – climate change

– food security

– energy supply

– globalisation of markets

– population growth

– economic growth

– declining natural resources.

Introduction

Ex-ante impact assessment using integrated models can be a

decision support tool to help with these decisions, if the models

Introduction

– systematically link development pathways with biophysical

and socioeconomic processes and characteristics

– integrate relationships across disciplines, levels of

organisation and scales

This presentation gives an (brief!) overview of the state of affairs of this multi-scale modeling of policy interventions

Introduction

Emphasis is on applications in developing countries

The presentation identifies key gaps in the current approaches to work truely across multiple integration levels, and suggests ways forward to deal with these gaps.

– Hot topic, a series of recent reviews:

– Creutzig et al., 2012, Nature Climate Change: Land use modellling

and LCAs

– Rounsevell et al., 2012, Land Use Policy: Future of multi-scale land

use modelling, important role for ABMs

– Verburg et al., 2013, Landscape Ecology: Land use modelling and

landscapes

– Verburg et al., 2013, COSUST: Land use modelling and food security

– Dumollard et al., 2013. CCAFS report: Comprehensive review of

large scale land use models

Multi-level modelling of land use

Current approaches either use

Modelling of land use and food production

– Top-down global and continental approaches (macro-economics and

large scale land use modeling (e.g. Zhang et al., 2013; Creutzig et

al., 2012); or

– Bottom-up approaches, from farm level upwards (farm household

modeling, micro-economics, agent based models and landscape

level land use modeling) (e.g. Rufino et al., 2011; Parker et al., 2003;

Valdivia et al., 2012).

– Large scale economic modelling of supply and demand for a given set of large regions

– Supply is met by allocation of land use

Large scale economic modelling of land use

Macro-scale economic model

Land use allocation

Crop productivity

Price formation

Livestock productivity

Land suitability

Demand

Large scale

Pixel level

ActualSupply

Needed Supply

Large scale economic modelling of land use

– Farm scale modelling (e.g. Rufino et al., 2011)

Bottom up, small scale approaches

Rufino et al., 2011. Ag Systems

Small scale studies: farm-scale modelling

– Farm scale modelling (e.g. Rufino et al., 2011)

Bottom up, small scale approaches

– Agent Based Modelling (e.g. An, 2012)

– Micro-economic approaches (with a farm description that goes beyond a simple production function!), e.g. Laborte et al., 2007; Valdivia et al., 2012)

Existing models do not sufficiently capture the complexity of

human–environment interactions across different scales

Modelling of land use and food production

Especially the link between landscape and local market

levels, and national and sub-national level policies and

markets is missing

There is clear separation between small scale and large

scale modelling approaches (one exception!)

Recommendation in many reviews (e.g. JRC, 2011; Creutzig et al., 2012, Rounsevell et al., 2012; Verburg et al., 2013a and 2013b):

Modelling of land use and food production

let bottom up models generate information that can be used in the formulations and parameter settings of large scale models

Macro-scale economic model

Land use allocation

Crop productivity

Price formation

Livestock productivity

Land suitability

Demand

Large scale

Pixel level

ActualSupply

Needed Supply

Large scale economic modelling of land use

Aggregation of responses of farm types

Changes in prices of products, inputs and labour.

Development pathways 1. Population2. rural – urban

connection3. Policies4. regional context5. cultural history

Derive summary functions for large scale models by using responses of small scale models

Market access

Agro-ecological potential

Aggregation of responses of individual farms or farm types

Derive summary functions for large scale models by using responses of small scale models

Changes in prices of products, inputs and labour.

Development pathways 1. Population2. rural – urban

connection3. Policies4. regional context5. cultural history

Farm distributionsN

um

be

r of

farm

s

Indicator of resource endowment

1 2 3a

3b

4

Potential financial returns of current soya cultivation on surplus land

1.25 USD/day

Hengsdijk et al., 2013

Aggregation of responses of individual farms or farm types

Local market

Derive summary functions for large scale models by using responses of small scale models

Aggregation of multi-agent land use responses

Derive summary functions for large scale models by using responses of small scale models

Aggregation of responses of individual farms or farm types within this type of landscape

Local market

Derive summary functions for large scale models by using responses of small scale models

Local market

Aggregation of multi-agent land use responseswithin this type of landscape

Derive summary functions for large scale models by using responses of small scale models

For these bottom up analyses to generate the right

information for large scale modelling exercises they will need

to be applied in contrasting sites

Derive summary functions for large scale models by using responses of small scale models

At the moment the data needs and model complexity of the

most advanced bottom up approaches will prohibit their

application in a large number of sites

The simpler approaches have already shown that they can be

applicable across large regions (e.g., SEAMLESS framework

in Europe, Ewert et al., 2011).

Derive summary functions for large scale models by using responses of small scale models

Agent-based approaches have been used to highlight the macro-scale patterns, especially in ecology, that emerge from interactions of heterogeneous agents at a lower scale (Grimm et al., 2005, Nature)

Derive summary functions for large scale models by using responses of small scale models

But whether this is a powerful approach for land use modelling at large scales still has to be proven (Rounsevell et al., 2012)

The existing gap between landscape and community to sub-

national market and policy levels prevents truely integrated

assessment of policy options.

Conclusions

In the different regions that are specified in the macro-economic models, different transition rules now apply, and those could be better informed by the bottom up model studies.

Conclusions

– Intensification versus expansion around rapidly developing urban centers

– Role of institutions, use of common resources (e.g. grazing land, forests, etc.) in specific regions

In small scale models clear improvements need to be made

in

Conclusions

- the description of effects of the distribution of local markets

on price formation

- the representation of farm diversity within existing large

scale maps of farming systems

Especially answering the question ‘how many are there of

which farms, and where are they located’ is pertinent.

Conclusions

Here remote sensing, farm characterisation surveys, and

market access and agro-ecological information need to come

together.

(virtually) All spatially explicit models take a pixel based

approach

Conclusions

Pixel is just a certain area, it does not represent a functional

unit (e.g. a farm livelihood, an institution)

Clearly, small scale model analyses can not easily be done

across the globe, but are typically targeted towards multi-

scale policy analyses in certain regions and in contrasting

sites.

Conclusions

Thanks for your attention!