Rural Road Impact Studies: Some Reflections

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Rural Road Impact Studies Some Reflections

• John Hine
• TUDTR
• World Bank

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Why study impact?

• General information about socio-economic
  conditions and use of roads ?
• To provide an indication of the impact on poverty
  reduction ?
• Research on a particular aspect ?
• A post evaluation of a particular road investment
  ?
• A detailed assessment of the impact of road
  investment in order to influence budgets, road
  planning criteria and road design ?

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How and when will rural road investment most
obviously promote development ?

• When there is a large change in transport costs
  This is dependent on change in road condition
  (new road or improvement) road length and mode of
  transport
• New and under-used resources of land and labor
  that can be brought into production
• Mobile capital and competitive markets
• Large external markets to absorb increased
  production

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Effects and impacts of road investment
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How do we find the impact of roads investment?

• Three main methods
• Historical before and after studies with controls
  
• (the double-difference approach)
• Geographical cross-sectional studies that compare
  areas with good access with poor access at the
  same time
• Macro econometric studies using regional time
  series data
• The methods may show an association or disprove a
  connection between roads and development but it
  is usually impossible to prove a causal link
  between road investment and development

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What came first the chicken or the egg?.

• Roads are not built or planned in a vacuum. The
  standard method of planning roads is to put them
  where the strongest growing demand is. Planners
  look at traffic levels and economic activity.
  Politicians are sensitive to those who shout the
  loudest.
• So if roads are built to serve the most dynamic
  areas and communities, and we later find that
  successful communities had road access but
  unsuccessful ones did not - what does this show?
• - It may only demonstrate conventional planning
  practise not that the roads caused the
  development!
• Hence there are dangers in basing an analysis
  just on the presence or absence of an investment.

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Why are so many road impact studies a
disappointment ?

• A failure to understand the rural economy and
  environment
• A failure to build in sufficient controls in the
  survey design
• A failure to explore alternative explanations
• The treatment of road impact as a black box so
  the causes of impact are not subject to detailed
  analysis
• A tendency to ignore how road investment affects
  fares, tariffs and vehicle accessibility
• Starting the before survey after road work has
  started
• Insufficient planning and funding for follow-up
  surveys
• Bad luck with factors beyond our control roads
  for improvement may not be completed and
  control roads get improved. New development
  initiatives occur and major (unrelated)
  investments take place.

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What are the factors that create differences and
variation in agricultural output ?

• In planning controls and analyzing impact we
  need to be aware of heterogeneity of rural areas
  and the range of factors that can cause variation
  over time.
• Altitude, soil fertility, crop composition
  (Should a tea growing area be a control for a
  coffee growing area?)
• Weather
• Animal and plant diseases and pests
• Secular and cyclical trends in output prices
• The pattern of previous planting of tree crops
• Availability and prices of inputs such as
  insecticide, fertilizer, labor, tractor hire and
  credit
• Government controls and policy and extension
  advice

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Some advice - If you want to influence road
planning 1.

• Do not base the analysis solely or primarily on
  the presence or absence of road investment. It is
  far better to base the analysis on measures of
  accessibility and transport costs.
• Collect data on road condition (passability,
  roughness), and on fares and freight tariffs to
  main markets and commodity prices at all survey
  stages. Relate this data to the road investment
  and to measures of welfare and output in order
  to determine impact.

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Some advice - If you want to influence road
planning 2.

• An analysis that focuses on transport costs is
  one of the few ways of-
• establishing a plausible relationship between
  road investment and measures of welfare and
  output
• Helping to overcome the chicken and egg problem
• differentiating the income effects of the initial
  investment from the longer term effects based on
  better accessibility

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An Ongoing Study in Ghana(by Vision and Optimal
Consultants)

• Baseline studies have been carried out all over
  Ghana involving
• 1,563 Household surveys
• 304 Passenger surveys
• 224 Vehicle operators
• 104 Focus group discussions
• Covering 42 Feeder Roads
• 11 Trunk Roads
• 8 Urban Roads

• Follow up studies will be undertaken in the same
  villages during 2006 and 2007

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• Transport Cost/Km

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Farmgate Prices

• Apart from the prices of two crops in the
  Northern Savanna, the prices that farmers receive
  for farm produce are higher along completed roads
  than uncompleted feeder roads.
• For example, in the Forest Zone, there is a
  substantial difference between the price of maize
  (213,000 per 100kg along completed roads and
  173,000 along uncompleted roads).

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Welfare and road condition

• Trip frequencies to hospital are higher on
  completed compared with uncompleted roads.
• 1.2 and 1.4 trips per household per year to
  hospitals along completed roads in the Savanna
  and Transitional Zones. While there were 1 and
  1.2 respectively in each Zone on uncompleted
  roads.

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• Average monthly income and expenditure per
  household
• Is higher along completed roads than uncompleted
  feeder roads for the same Climatic Zone. (As with
  other surveys reported expenditure exceeds
  reported income).

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Observations on the current Ghanaian Study

• Two consultants appointed. Initially each wanted
  their own surveys, computerization and methods of
  data analysis. The methodologies were overly
  complex, paid insufficient attention to observed
  transport costs and would have prevented a
  comprehensive cross-country analysis. Now a
  common approach has been adopted.
• Many of the initial before surveys were started
  well after road investment had started.
• We noticed a pattern emerging between complete
  and incomplete feeder roads and the current
  cross-sectional analysis is based on this.

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Earlier (1980) Case Study In GhanaLocation of
survey villages in Ashanti Region
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A study of 33 villages in the Ashanti Region of
Ghana 1.

• Inaccessible villages
• more dependent on agriculture
• more labour input into farming
• more sheep goats and poultry
• more cocoa grown and sold per farmer
• greater use of fertiliser, insecticide, extension
  and tractor hire
• greater proportion of plantain sold

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A study of 33 villages in the Ashanti Region of
Ghana 2.

• Accessible villages
• more dependent on non-farming jobs
• more trip making
• more success in loan finance
• greater proportion of cassava sold
• No difference
• Cocoa sales per hectare
• maize yields or proportion of maize sold

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Potential improvement of farmgate prices
Percentage increase in farm-gate price of maize
with improved access
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Lessons from the earlier Ghanaian study

• Short distance road improvements likely to have
  little impact on development
• The is a very important need for basic access to
  ensure vehicles can pass
• Small scale spot improvements to ensure access
  are likely to provide best value for money

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Observations on the earlier Ghanaian Study

• Insufficient attention paid to directly finding
  out transport tariffs, or state of the roads, for
  each location and perhaps too much reliance on a
  generalized model of transport costs.
• No analysis of overall income/expenditure or
  welfare
• The main cash crop Cocoa- was purchased at a
  uniform price throughout the country. Hence
  improved roads would make little difference when
  growing and selling cocoa.
• The overall state of the Ghanaian economy at the
  time was in a dreadful state and in terms of what
  farmers could buy for their efforts there was
  little incentive to respond to price signals.