**Paul-Antoine Bontinck**
@
on

Is it possible to implement engineering constraints on the Supply matrix and the Import matrix?

Hi all,

I am delving deep in the IELab's output at the moment, and need some help understanding a couple of things with regards to the Supply matrix and the RoW import matrix. Apologies if my questions are obvious or unclear.

I'll give you a little bit of background to start with. We're working on a hybrid model using highly disaggregated input-output data out of the IELab - we were originally using the IOPC09 classification (which has 1284 sectors). As we started analysing some of the data a bit further, we started to see strange things in the output. For instance, looking at greenhouse gas emissions, we found that Gold bullions are one of the most significant transaction in the production of Aluminium bars, which doesn't seem to make sense. This is because at this very high level of disaggregation, entire sections of the base table are weakly constrained, so some of the numbers in the Base Table can be pretty random. At lease this is my understanding. One of the way forward, advised by Manfred, was to work on a set of Engineering constraints, which would basically provide the IELab with a list of transaction that should not occur when we know that they do not make sense. There is a Engineering constraint matrix on Nina which I used as a starting point.

I was able to develop this set of constraints for the Use table and write the necessary ALANG commands. However, I wasn't able to replicate this for the Supply table (although I prepared a second set of constraints). **My first question is: Are there any obvious reasons for a set of engineering constraints not to work on the Supply table?** Or is it likely that I made an error somewhere in the ALANG command? Or somewhere on the actual constraint file?

In addition, I get the IELab to provide the RoW table of imports at the same level of disaggregation. This section of the SUT raise similar issues, which I don't seem to be able to correct using the engineering constraints. I am using the ABS5209, ABS5215 and Balancing contraints, which I know include some information on Imports (I think ABS5209 include the 111x111 matrix of import). My second question is: **Are there any reason for me not to be able to use a set of engineering constraints on the Import matrix?** My initial thought was that the same set of engineering constraint could be used both by the Use and Imports matrices.

If anyone has advice on how to move forward, that would be greatly appreciated!! Sorry for the very long post.

Cheers

Polo