Title: Thinking about Impact Assessment - from an International Development Cooperation standpoint
1Thinking about Impact Assessment - from an
International Development Cooperation standpoint
- Professor Elliot Stern, Lancaster University UK
- Presentation to ALNAP 24th Biannual
- Berlin December 2nd 2008
2Thinking about Impact Assessment
- The argument I want to make
- Outcomes, results, effects and impacts
are important - But we need to think clearly about why this is
so what methods are appropriate and in what
circumstance
3Thinking about Impact Assessment
- Evaluators have always been interested in
outcomes, results, effects and impacts - The balance between summative and formative,
process and outcome evaluations has been
argued about , and - There have been legitimate criticisms that too
much attention given to process not outcomes
4Thinking about Impact Assessment
- There are often weaknesses in evaluation
- The balance of evaluative effort can be skewed
towards processes unconnected to outcomes - Methods adopted make little effort to disentangle
what works from what is spurious from what is
due to a particular intervention/initiative or to
other causes - Evaluators have been known only to be concerned
for beneficiaries ignoring those who have
missed out - Initial success is privileged not longer term
results
5Thinking about Impact Assessment
- In development cooperation the OECD/DAC
definition has emphasised duration in defining
impacts impacts are - long term effects produced by a development
intervention - Not all have accepted this distinction even in
this particular policy domain, thus EU defines
impact as - A general term used to describe the effects of
an intervention on society
6Thinking about Impact Assessment
- There has been a general upsurge of interest in
experimental, scientific which have informed
the discourse about impact across many domains. - This has been linked to medical trials -Cochrane
Collaboration and similar moves in human services
Campbell Collaboration and reinforced by US
legislation requiring evaluations to be
scientific
7Thinking about Impact Assessment
- Impact has in this context been given a
narrower methods-led meaning, to paraphrase Mohr - A comparison of what happens with what would have
happened had the intervention not been
implemented - From this perspective - the one advocated by
Howard White at 3ie and the GDC - impact has
become identified with attribution and the
counterfactual and experimental methodologies
associated with that understanding of science
research - (see GDC Report When Will We Ever Learn?
- Improving Lives through Impact Evaluation 2006)
8Thinking about Impact Assessment
- This is not the first time this model has been
advocated - it recurs. It is not generally
accepted in the evaluation community as the only
or superior approach but it is important. - The battles that have gone on in the NONIE group
and elsewhere have forced some acceptance of a
mix of methods, fit for purpose and
circumstance. - But we would be wise to continue to distinguish
between this and other approaches to impact
9Thinking about Impact Assessment
- Why does attribution matter?
- Mainly because we need to disentangle what makes
a difference, what works in the jargon, from
changes that have nothing to do with our efforts - Not simply was this initiative successful?
- Also
- Did this initiative/intervention make a
difference that would not otherwise have
happened? - For example
10Thinking about Impact Assessment
C
C
Figure 1
Figure 3
A
B
B
A
B(2)
C
Figure 2
A
B(1)
D
11Thinking about Impact Assessment
- There are two complementary approaches to this
problem - Comparative methods, including before/after
comparisons quasi experiments and full
(randomised) experiments - Theory-based methods including Theories of
Change, causal modelling and realist analyses - We usually need a mix!
12Thinking about Impact Assessment
- There are 4 sets of considerations I would use
when considering how to construct an approach to
the evaluation of impacts - The political agendas of the actors
- Technical issues of what is possible
- Arguments from the philosophy of science
- Ethical considerations
13Thinking about Impact Assessment
- The narrow approach to impact does have political
drivers although they are very diverse and the
alliances are sometimes strange. Advocates want
obviously to better meet social and economic
needs. But they also may want to - Legitimate (or de-legitimate) institutional and
policy goals - Simplify policies/find the silver bullet/reduce
costs/risks - Reduce public expenditure the nothing works
agenda, again.. and on a smaller scale - Occupational politics or careerism
14Thinking about Impact Assessment
- Technical considerations are well-rehearsed. They
include - Problems constructing and maintaining control
groups - The practicalities of random allocation (central
control, administrative capacity, resources) - The risks of contamination
- The tendency to reductionism a focus on
limited outcomes of interest - The statistical power of measures (sample size)
- Trade-offs between internal validity and external
validity hence our ability to generalise
15Thinking about Impact Assessment
- I would want to distinguish between practical
risks and logistical difficulties on the one hand
and fitness for purpose - Many objections to experimental
quasi-experimental methods- when they are
appropriate - can be overcome with careful
attention to procedures and protocols but
sometimes difficulties are rooted in the object
and its context as well as in methods
16Thinking about Impact Assessment
- We can compare three scenarios
- S1 Standardized interventions in identical
settings with common beneficiaries - S2 Standardized interventions in diverse
settings, possibly with diverse beneficiaries - S3 Customized interventions in diverse settings
with diverse beneficiaries
17Thinking about Impact Assessment
- These scenarios necessarily pull for different
methodologies - Scenario 1 is better adapted to experiments
- Scenario 2 is better adapted to quasi experiments
comparisons (contingent and realist) and
combinations of methods - Scenario 3 is better adapted to case studies or
narrative/qualitative approaches that build
plausible theories
18Thinking about Impact Assessment
- Experiments do tend to favour single inputs and
outcomes that can be delivered in discrete
packages (not embedded) and that have a
relatively short implementation chain in the
sense both of time and complexity/ease of
implementation and where the intervention is
repeated often (large n) - They are best for projects that deliver a known
service to large numbers of recipients are
possible for relatively simple programmes
unsuited to complex multi-measure strategies/
policies.
19Thinking about Impact Assessment
- This is acknowledged even by protagonists of
RCTs. For example Esther Duflo of the MIT Poverty
Lab has noted - randomised evaluations are not suitable for all
types of programmes. They are suitable for
programmes that are targeted to individuals or
communities, and where the objectives are well
defined. For example, the efficacy of foreign aid
disbursed as general budget support cannot be
evaluated in this way.
20Thinking about Impact Assessment
- There is however a danger that advocates of
narrower impact approaches will press to
redefine policy measures so that they become
evaluable through their preferred methods. As
Duflo went on to say - It may be desirable, for efficiency or political
reasons, to disburse some fraction of aid in this
form GBS, although it would be extremely costly
to distribute all the foreign aid in the form of
general budget support, precisely because it
leaves no place for rigorous evaluation of
projects. (Italics added)
21Thinking about Impact Assessment
- In international development cooperation, there
is a tendency for advocates of impact
approaches to also favour sectoral, targeted
programmes (sometimes called vertical
interventions) rather than policies that seek to
address wider issues of governance and
institution-building such as General Budget
Support or the Paris Declaration - arguing that
sectoral programmes are both likely to be more
effective and are often cheaper to deliver of
timely relevance given MDG goals
22Thinking about Impact Assessment
- Philosophical objections to experiments (and
randomisation in particular) go to the heart of
hard-fought debates about causality in the social
sciences. These are variously - Epistemological what we know and how
- Ontological - the nature of knowledge
- Methodological the possibilities of data
collection and analysis - To pick up on a few examples of these debates .
23Thinking about Impact Assessment
- Newtonian science assumed that we can observe
regularities or patterns of individual phenomena
from the outside this allows for consistent
explanations explanation can be derived
empirically - Most contemporary understandings of causality are
theory based assume we cannot observe causal
mechanisms we need to open up the black-box
because a) causal mechanisms are often hidden and
b) are often unstable e.g. are context specific - Hence difficulty in finding Humean general laws!
24Thinking about Impact Assessment
- If we follow this line of arguments it is
unlikely we will ever be able to consistently
demonstrate what works even for relatively
straightforward projects and programmes across
all contexts and circumstances evidence remains
a matter of probability and estimation not
certainty or truth
25Thinking about Impact Assessment
- Which is why there is a need for
- Multi-methods that can be triangulated
- Theory based approaches to understand
mechanisms that cannot be fully observed - Distinguishing between causality explanation
- Recognising the limits of proof and certainty
- Understanding and typologising contexts
- Linking process evaluations with outcome/impacts
so as to understand a) what is being implemented
and b) what accounts for divergence/diversity
26Thinking about Impact Assessment
- The ethical difficulties that all applied
research faces are also well documented - Treating people as actors with agency and will
rather than as passive objects - Denying an intervention from some if it is needed
in order to achieve randomisation - Although the latter can be an unfounded it would
be consistent with counterfactual logic to offer
alternatives in terms of service rather than
something/nothing the focus of experiments are
often modes of delivery not the actual service
27Thinking about Impact Assessment
- To conclude
- We do need to focus more on outcomes/effects/impac
ts - Comparisons (including experiments) are important
as are model/theory building - We need to accept that as initiatives become more
complex and multi-measure so certainty and
predictability about what works will diminish - We should neither be put-off nor seduced by the
promises of experimentalists they offer many
things but in a limited set of circumstances
as the wise ones among them admit!
28Thinking about Impact Assessment