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Objectives. Inform the production units about the Eurostat IT tools available for Temporal Disaggregation and Seasonal Adjustment Identify audience for a possible internal courses (including demo session) at ESTAT on the subject No methodological issues will be addressedNo software demo, only screenshots.
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1. Introduction to Ecotrim and DEMETRA+
2. Objectives Inform the production units about the Eurostat IT tools available for Temporal Disaggregation and Seasonal Adjustment
Identify audience for a possible internal courses (including demo session) at ESTAT on the subject
No methodological issues will be addressed
No software demo, only screenshots
3. Contents Summary information on ECOTRIM (30 mins)
Summary information on DEMETRA+ with briefing on the ESS guidelines on Seasonal Adjustment (30 mins)
User support provided by Unit B2 Methodology and Research (10 mins)
Q & A (20 mins)
4. Why Ecotrim and DEMETRA+ together? Target users are the same
6. Topics Ecotrim in the framework of data production
Techniques available in Ecotrim
7. Forewords Ecotrim is a program written for Windows and has been developed by Eurostat
There is a project within Eurostat (UNIT C2) for the development/maintenance of the program
The main aim of this presentation is to demonstrate the potential of the application
User manual is available in EN and FR
http://circa.europa.eu/Public/irc/dsis/ecotrim/library
8. Why Eurostat developed Ecotrim? ESA 95 paragraph 12.04
The statistical methods used for compiling quarterly accounts
..can be classified in two major categories: direct procedure and indirect procedure
... indirect procedures are based on Temporal Disaggregation of the annual accounts data in accordance with mathematical and statistical methods using reference indicators that permit the extrapolation for the current year
9. Definitions Temporal Disaggregation
Process of deriving high frequency data from low frequency data and, if available, related high frequency information
ECOTRIM
Supplies a set of mathematical and statistical techniques to carry out Temporal Disaggregation
10. Temporal Disaggregation techniques are useful in compiling short-term statistics: Quarterly National Accounts (QNA)
Give a quarterly breakdown of the figures in the annual accounts
Flash estimates
Use the available information in the best possible way including, in the framework of a statistical model, the short-term available information and the low frequency data in a coherent way
Monthly indicators of GDP
The monthly estimates are derived from the available information respecting the coherence with quarterly data
11. Other short-term statistics Short-term industrial statistics
Employment
Money and banking statistics
12. Techniques available in Ecotrim
13. Basic principles Distribution
When annual data are either sums or averages of quarterly data (e.g., GDP, consumption, indexes and in general all flow variables and all average stock variables)
Interpolation
When annual value equals by definition that of the fourth (or first) quarter (e.g., population at the end of the year, money stock, and all stock variables)
Extrapolation
When estimates of quarterly data are made when the relevant annual data are not yet available
14. Techniques available in Ecotrim Temporal Disaggregation of univariate time series by using or not related series and fulfilling temporal aggregation constraints
Mathematical approach and the optimal, in the least squares sense, approach
Temporal Disaggregation of multivariate time series with respect of both temporal and contemporaneous aggregation constraints
Flash estimates of current year observations by using or not available information on related series
15. Temporal and Accounting constraint Statistical offices are often faced with the estimation of a set of quarterly series linked by some accounting relationship
Temporal Disaggregation methods can also be used in such cases, to give a solution consistent with both temporal and accounting aggregation constraints
16. Estimates have to be consistent and coherent Temporal consistency
Quarterly values have to match annual values (for example the sum of quarterly values of the GDP must be equal to the annual value)
Accounting coherence
Quarterly components of an account should respect the accounting constraints (for example, the sum of quarterly values of the GDP expenditure side components should be equal to the corresponding quarterly value of GDP)
17. Temporal Disaggregation methods Univariate Approach
Smoothing methods
Two steps adjustment methods
Time series methods
Regression based methods
Static models
Dynamic models
Multivariate Approach
Two steps adjustment methods
Regression based methods
18. The classical univariate Temporal Disaggregation Given the annual observations for an account aggregate and the quarterly values for a related series, the unknown quarterly/monthly values of the aggregate are estimated
Chow and Lin (1971) worked out a least-squares optimal solution on the basis that a linear regression model involving the quarterly aggregate series and the related quarterly series will hold
19. Statistics Rhô
R-squared ( next to 1)
Durbin-Watson ( about 2 )
Probability of F
T-stat
Reliability indicators (lower value for the range between Min and Max)
20. Reminders It must be reminded that the statistics obtained within Ecotrim outputs are based on the annual data
It is advisable to use a unique model all along the series
Structural breaks must be taken in consideration
It is advisable to have observations covering at least 20 years when disaggregating annual data
It is advisable to have observations covering at least 15 years when disaggregating quarterly data
21. ECOTRIM ECOTRIM is a program that supplies a set of mathematical and statistical techniques to carry out Temporal Disaggregation
Structured for Windows 95/98 and Windows NT
Visual Basic and C++
User friendly
It can be used according to two different modes:
Interactive mode
Batch mode
22. Interactive mode
23. Batch mode ECOTRIM performs Temporal Disaggregation of several jobs
starting from a batch command file
Batch mode is very useful when handling many series
24. Work with ECOTRIM
25. Work with ECOTRIM
26. Work with ECOTRIM
27. Work with ECOTRIM
28. Work with ECOTRIM
29. Work with ECOTRIM
30. Future of Ecotrim Updating the Visual Basic/C++ version and refurbish the interface of ECOTRIM with the purpose to match production and users requirements
Design of the application as a Building Block, CVD compliant
Make system Windows 7 compatible, compilation as a 64-bit application (former was 16-bit)
Inclusion of more recent methods like:
Univariate Regression based Temporal Disaggregation
Reconciliation by Two-Step procedures (Quenneville & Rancourt 2005 Di Fonzo & Marini 2009)
31. DEMETRA+
32. What is DEMETRA+?
34. Why DEMETRA+?
36. How to work with DEMETRA+
41. How to work with DEMETRA+
42. How to work with DEMETRA+
43. How to work with DEMETRA+
50. ESS Guidelines on SA
55. EUROSTAT UNIT B2
56. Questions?