Dear Soufiene Assidi. I found this article. The paper suggests a few models. I hope it can help you in finding suitable model.

Regards.

 These are some other related articles. I hope they are useful. Thank you.

http://ucrel.lancs.ac.uk/cfie/Conf2013/VivienBeattie.pdf

http://vmdev1.eprints.org/334/1/Beattieaccforum28.pdf

http://eprints.bham.ac.uk/1276/1/rowbottom_2010_jofappliedaccount.pdf

http://cfg.org.uk/~/media/Document%20library/02%20Reporting/04%20Impact%20Reporting%20incl%20narrative%20reporting/Accounting_Narratives_The_Reporting_Practices_of_British_Charities_1001QUSH0003.ashx

http://irserver.ucd.ie/bitstream/handle/10197/4949/03_14_Brennan_Merkl-Davies_Accounting_Narratives_and_Impression_Management.pdf?sequence=1

It is essential that you first establish your purpose in measuring narratives (or their content).

There are well established text-centered approaches if you are merely concerned with readability (e.g.  Flesch, FOG and Lix indices). If you are concerned with understandability, you need a reader-centered approach. The paper from Mr Kadri (Jones & Smith 2014) provides a useful review regarding the use of understandability measures.

If you are concerned with message content, other approaches should be considered. 

I used content analysis for a paper which I prepared about audit committee which you will find in research gate articles. Good luck

Thanks  for all response 

I would like study the quality of information and accounting narratives report.

Is there a model econometric for this study

I tried also to analyse the quality  (relevance, comparability) of information in accounting narratives in this papers:

http://novintarjome.com/wp-content/uploads/2014/02/Human-resources.pdf

https://www.researchgate.net/publication/281945358_Human_capital_information_in_management_reports_An_analysis_of_compliance_with_the_characteristic_of_the_relevance_of_disclosure

Article Human capital information in management reports: An analysis...