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NTTS Conference, Brussels, 18-20 February 20091 OECD/JRC Handbook on constructing composite indicators- Putting theory into practice Michela Nardo & Michaela.

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Presentation on theme: "NTTS Conference, Brussels, 18-20 February 20091 OECD/JRC Handbook on constructing composite indicators- Putting theory into practice Michela Nardo & Michaela."— Presentation transcript:

1 NTTS Conference, Brussels, February OECD/JRC Handbook on constructing composite indicators- Putting theory into practice Michela Nardo & Michaela Saisana & JRC-IPSC- G09 Econometric and Applied Statistics Unit NTTS (New Techniques and Technologies for Statistics) Seminar Brussels, February 2009

2 NTTS Conference, Brussels, February Step 1. Developing a theoretical framework Step 2. Selecting indicators Step 3. Imputation of missing data Step 4. Multivariate analysis Step 5. Normalisation of data Step 6. Weighting and aggregation Step 7. Robustness and sensitivity Step 8. Back to the details (indicators) Step 9. Association with other variables Step 10. Presentation and dissemination The ten recommended steps JRC/OECD Handbook on composite indicators [… and ranking systems] 2 rounds of consultation with OECD high level statistical committee Finally endorsed in March 2008

3 NTTS Conference, Brussels, February What is badly defined is likely to be badly measured…. This means : To give a definition of the phenomenon to describe To define the number and identity of indicators To describe the nested structure of these indicators Step 1. Developing a Theoretical/conceptual framework

4 NTTS Conference, Brussels, February Step 1. Developing a Theoretical/conceptual framework

5 NTTS Conference, Brussels, February Framework: a way of encoding a natural/social system into a formal system No clear way Definition of the phenomenon Systems are complex A framework is valid only within a given information space Formal coherence but also reflexivity Step 1. Developing a Theoretical/conceptual framework

6 NTTS Conference, Brussels, February Problems found in practice… Go from an ideal to a workable framework Recognize that a framework is only a possible way of representing the reality Recognize that a framework is shaped by the objective of the analysis – implies the definition of selection criteria (e.g. input, process, output for measuring innovation activity) Define the direction of an indicator (i.e. define the objective of the CI). E.g. social cohesion – OECD lists 35 indicator among which number of marriages and divorces, the fertility rate, number of foreigners,.. BUT Does a large group of foreign-born population decrease social cohesion? Select sound variables (merge different source of information, soft data, different years, …) Step 1. Developing a Theoretical/conceptual framework

7 NTTS Conference, Brussels, February A composite indicator is above all the sum of its parts… Step 2. Selecting variables

8 NTTS Conference, Brussels, February Dempster and Rubin (1983), The idea of imputation is both seductive and dangerous Step 3. Imputation of missing data

9 NTTS Conference, Brussels, February Rule of thumb: (Little Rubin 87) If a variable has more than 5% missing values, cases are not deleted, and many researchers are much more stringent than this. Case deletion Pros: no artificial assumptions Cons: higher standard error (less info is used) Risk: think that the dataset is complete Step 3. Imputation of missing data

10 NTTS Conference, Brussels, February Imputation with MAR and MCAR assumptions Single imputation: one value for each missing data implicit modeling explicit modeling Multiple imputation: more than 1 value for each missing data (Markov Chain Monte Carlo algorithm) Step 3. Imputation of missing data

11 NTTS Conference, Brussels, February Analysing the underlying structure of the data is still an art … Step 4. Multivariate Analysis

12 NTTS Conference, Brussels, February Grouping information on individual indicators Is the nested structure of the composite indicator well-defined? Is the set of available individual indicators sufficient/ appropriate to describe the phenomenon? Expert opinion and Multivariate statistics Revision of the indicators or the structure Step 4. Multivariate Analysis

13 NTTS Conference, Brussels, February Correlation one may see a high correlation among sub- indicators as something to correct for, e.g. by making the weights inversely proportional to the strength of the overall correlation for a given sub-indicator, e.g. Index of Relative Intensity of Regional Problems in the EU (Commission of the European Communities, 1984). schools of thought Practitioners of multicriteria decision analysis would instead tend to consider the existence of correlations as a feature of the problem, not to be corrected for, as correlated sub-indicators may indeed reflect non-compensable different features of the problem. e.g. A cars speed and beauty are likely correlated with one another, but this does not imply that we are willing to trade speed for design. Step 4. Multivariate Analysis

14 NTTS Conference, Brussels, February Step 4. Multivariate Analysis Principal Component Analysis

15 NTTS Conference, Brussels, February Grouping information on countries/indicators Cluster analysis serves as: a purely statistical method of aggregation of the indicators, a diagnostic tool for exploring the impact of the methodological choices made during the construction phase of the composite indicator, a method of disseminating information on the composite indicator without losing that on the dimensions of the individual indicators, and a method for selecting groups of countries to impute missing data with a view to decreasing the variance of the imputed values. Cluster analysis Step 4. Multivariate Analysis

16 NTTS Conference, Brussels, February Cluster analysis: group information on countries based on their similarity on different individual indicators. Step 4. Multivariate Analysis

17 NTTS Conference, Brussels, February Avoid adding up apples and oranges … Step 5. Normalisation of data

18 NTTS Conference, Brussels, February Convert variables expressed in different measurement units (e.g. no. of people, money per capita, % of total exports) into a single (dimensionless) unit Issue: which is the most suitable normalization robustness Step 5. Normalisation of data

19 NTTS Conference, Brussels, February Pro: simple, indep. to outliers Cons: levels lost Pro: no distortion from mean Cons: outliers Pro: simple Cons: outliers Pro: benchmarking Cons: max be outliers Pro: reduce skewness Cons: values near to 0 Pro: indep on slight changes in def. Cons: no track slight improvements Step 5. Normalisation of data

20 NTTS Conference, Brussels, February Pro: simple, no outliers Cons: p arbitrary, no absolute levels Pro: minimize cycles Cons: penalize irregular indic. Pro: based on opinions Cons: no absolute levels Pro: no levels but changes Cons: low levels are equal to high levels Step 5. Normalisation of data

21 NTTS Conference, Brussels, February The relative importance of the indicators is a source of contention … 6. Weighting and aggregation should be done along the lines of the underlying theoretical framework. To select appropriate weighting and aggregation procedure(s) that respect both the theoretical framework and the data properties. To discuss whether correlation issues among indicators should be accounted for. To discuss whether compensability among indicators should be allowed. Step 6. Weighting and aggregation

22 NTTS Conference, Brussels, February No general consensus A composite cannot be objective Weighting implies a subjective choice Soundness and transparency Step 6. Weighting and aggregation

23 NTTS Conference, Brussels, February Weights based on statistical models Factor analysis Benefit of the doubt Regression Unobserved components model Weights based on opinions Budget allocation Public opinion Analytic hierarchy process Conjoint analysis

24 NTTS Conference, Brussels, February Pros: deals with correlation Cons: correlation does not mean redundancy only used when correlation sensitive to factor extraction and rotation Factor analysis Step 6. Weighting and aggregation

25 NTTS Conference, Brussels, February The performance indicator is the ratio of the distance between the origin and the actual observed point and that of the projected point in the frontier:. Step 6. Weighting and aggregation Benefit of the doubt Data Envelopment Analysis (DEA) employs linear programming tools to estimate an efficiency frontier that would be used as a benchmark to measure the relative performance of countries

26 NTTS Conference, Brussels, February Benefit of the doubt Pros: * the composite will be sensible to national priorities * real benchmark * any other weighting scheme gives a lower index * reveal policy priorities Cons: * weights are country specifics (no comparability) * a priori constraints on weights * weights depend on the benchmark Step 6. Weighting and aggregation But the cross-efficient DEA allows ranking (and comparability)

27 NTTS Conference, Brussels, February Budget allocation The budget allocation process (BAP) has four different phases: Selection of experts for the valuation; Allocation of budget to the individual indicators; Calculation of the weights; Pros: weights not based on statistical manipulation experts tends to increase legitimacy and acceptance Cons: reliability (weights could reflect local conditions) not suited for more than 10 indicators at the time Step 6. Weighting and aggregation

28 NTTS Conference, Brussels, February Analytic hierarchy process The core of AHP (Saaty 70s) is an ordinal pair-wise comparison of attributes. The comparisons are made per pairs of individual indicators: Which of the two is the more important? And, by how much? The preference is expressed on a semantic scale of 1 to 9. A preference of 1 indicates equality between two individual indicators, while a preference of 9 indicates that the individual indicator is 9 times more important than the other one. The results are represented in a comparison matrix (Table 20), where Aii = 1 and Aij = 1 / Aji. Step 6. Weighting and aggregation

29 NTTS Conference, Brussels, February Analytic hierarchy process Pros: suitable for qualitative and quantitative data Cons: high number of pairwise comparisons depends on the setting of the experiment Step 6. Weighting and aggregation

30 NTTS Conference, Brussels, February Aggregation rules: Linear aggregation implies full (and constant) compensability rewards sub-indicators proportionally to the weights Geometric mean entails partial (non constant) compensability rewards more those countries with higher scores The absence of synergy or conflict effects among the indicators is a necessary condition to admit either linear or geometric aggregation & weights express trade-offs between indicators Multi-criteria analysis different goals are equally legitimate and important (e.g. social, economic dimensions), thus a non-compensatory logic Step 6. Weighting and aggregation

31 NTTS Conference, Brussels, February When different goals are equally legitimate and important, then a non compensatory logic may be necessary. Example: physical, social and economic figures must be aggregated. If the analyst decides that an increase in economic performance can not compensate a loss in social cohesion or a worsening in environmental sustainability, then neither the linear nor the geometric aggregation are suitable. Instead, a non-compensatory multicriteria approach will assure non compensability by formalizing the idea of finding a compromise between two or more legitimate goals. + does not reward outliers + different goals are equally legitimate and important + no normalisation is required BUT - computational cost when the number of countries is high Multi-criteria type of aggregation Step 6. Weighting and aggregation

32 NTTS Conference, Brussels, February Step 7. Robustness and sensitivity Cynics say that models can be built to conclude anything provided that suitable assumptions are fed into them. [The Economist, 1998] many indices rarely have adequate scientific foundations to support precise rankings: […] typical practice is to acknowledge uncertainty in the text of the report and then to present a table with unambiguous rankings [Andrews et al. (2004: 1323)] Step 7. Robustness and Sensitivity

33 NTTS Conference, Brussels, February Uncertainty + Sensitivity Analysis

34 NTTS Conference, Brussels, February stakeholder involvement Steps in the Development of an Index Step 1. Developing a theoretical framework Step 2. Selecting indicators Step 3. Imputation of missing data Step 4. Multivariate analysis Step 5. Normalisation of data Step 6. Weighting and aggregation Step 7. Robustness and sensitivity Step 8. Links to other variables Step 9. Back to the details Step 10. Presentation and dissemination Sources of uncertainty

35 NTTS Conference, Brussels, February As a result, an uncertainty analysis should naturally include a careful mapping of all these uncertainties (/assumptions) onto the space of the output (/inferences). Two things can happen: The latter outcome calls in turn for a revision of the ranking system, or a further collection of indicators. The space of the inference is still narrow enough, so as to be meaningful. The space of the inference is too wide to be meaningful.

36 NTTS Conference, Brussels, February JRC/OECD Handbook on composite indicators [… and ranking systems] Why the ten steps? The three pillars of a well-designed CI: 1.Solid conceptual framework, 2.good quality data, 3.sound methodology (+ robustness assessment) Composite indicators between analysis and advocacy, Saltelli, 2007, Social Indicators Research, 81:65-77 If the 3 conditions are met then CIs can be used for policy-making

37 NTTS Conference, Brussels, February Some recent CIs developed in collaboration with the JRC using the philosophy of the Handbook 2008 European Lifelong Learning Index (Bertelsmann Foundation, CCL) 2008/2006 Environmental Performance Index (Yale & Columbia University) 2007 Alcohol Policy Index (New York Medical College) 2007 Composite Learning Index (Canadian Council on Learning) 2002/2005 Environmental Sustainability Index (Yale & Columbia University) JRC/OECD Handbook on composite indicators [… and ranking systems]

38 NTTS Conference, Brussels, February The Composite Learning Index (Canadian Council on Learning) Results Policy messageSensitivity analysis Composite Learning Index (Canadian Council on Learning) Framework

39 NTTS Conference, Brussels, February Framework (WHO report) Results Policy message Sensitivity analysis The Alcohol Policy Index (New York Medical College) Comparative Analysis of Alcohol Control Policies in 30 Countries Brand, Saisana, Rynn, Pennoni, Lowenfels, 2007, PLoS Medicine, 4(4):

40 NTTS Conference, Brussels, February The Alcohol Policy Index (New York Medical College) Maybe an example of a country where strong laws are poorly enforced. high estimated amount of unrecorded consumption (>50% of the total). predominantly Islamic population

41 NTTS Conference, Brussels, February Our Tools for Sensitivity Analysis free software Two fractional variance measures First order effect – one factor influence by itself Total effect - influence inclusive of all interactions with other factors

42 NTTS Conference, Brussels, February Saltelli A., M. Ratto, T. Andres, F. Campolongo, J. Cariboni, D. Gatelli, M. Saisana, S. Tarantola, 2008, Global sensitivity analysis. The Primer, John Wiley & Sons, England. OECD/JRC, 2008, Handbook on Constructing Composite Indicators. Methodology and user Guide, OECD Publishing, ISBN Authored by Nardo M., Saisana M., Saltelli A., Tarantola S., Hoffman A., Giovannini E. Selected References Books

43 NTTS Conference, Brussels, February Brand, D. A., Saisana, M., Rynn, L. A., Pennoni, F., Lowenfels, A. B., 2007, Comparative Analysis of Alcohol Control Policies in 30 Countries, PLoS Medicine 4(4): Cherchye, L., Moesen, W., Rogge, N., van Puyenbroeck, T., Saisana, M., Saltelli, A., Liska, R., Tarantola, S., 2008, Creating Composite Indicators with DEA and Robustness Analysis: the case of the Technology Achievement Index, Journal of Operational Research Society 59: Saisana, M., Saltelli, A., Tarantola, S., 2005, Uncertainty and sensitivity analysis techniques as tools for the analysis and validation of composite indicators, Journal of the Royal Statistical Society A 168(2): Saltelli, A., M. Ratto, S. Tarantola and F. Campolongo (2005) Sensitivity Analysis for Chemical Models, Chemical Reviews, 105(7) pp 2811 – Munda G., Nardo M., Saisana M., 2009, Measuring uncertainties in composite indicators of sustainability. Int. J. Environmental Technology and Management (forthcoming). Selected References Journal articles

44 NTTS Conference, Brussels, February Munda G., Saisana M., 2009, Methodological Considerations on Regional Sustainability Assessment based on Multicriteria and Sensitivity Analysis. Regional Studies (forthcoming). Tarantola S., Nardo M., Saisana M., Gatelli D., 2006, A new estimator for sensitivity analysis of model output: An application to the e-business readiness composite indicator. Reliability Engineering & System Safety 91(10-11), Selected References Journal articles

45 NTTS Conference, Brussels, February Saisana, M., 2008, The 2007 Composite Learning Index: Robustness Issues and Critical Assessment, EUR Report EN, European Commission, JRC-IPSC, Italy. Saisana M., DHombres B., 2008, Higher Education Rankings: Robustness Issues and Critical Assessment, EUR Report EN, European Commission, JRC-IPSC, Italy. Saisana M., Munda G., 2008, Knowledge Economy: measures and drivers, EUR Report EN, European Commission, JRC-IPSC. Saisana M., Saltelli, A., 2008, Sensitivity Analysis for the 2008 Environmental Performance Index, EUR Report EN, European Commission, JRC-IPSC. Selected References EUR reports

46 NTTS Conference, Brussels, February Munda G. and Nardo M. (2005), Constructing Consistent Composite Indicators: the Issue of Weights, EUR EN, Joint Research Centre, Ispra. Nardo M., Tarantola S., Saltelli A., Andropoulos C., Buescher R., Karageorgos G., Latvala A. and Noel F. (2004), The e-business readiness composite indicator for 2003: a pilot study, EUR Saisana M., Tarantola S., 2002, State-of-the-art Report on Current Methodologies and Practices for Composite Indicator Development, EUR Report EN, European Commission, JRC-IPSC, Italy. Selected References EUR reports


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