Why don't major research institutions systematically publish their subscription fees to scientific journals? I read on https://ropengov.github.io/r/2016/06/10/FOI/:

Finland becomes to our knowledge the first country where annual subscription fees for all individual publishers and all major research institutions have been made available.
[…]
Limited access to detailed pricing information and agreement details are likely to result in suboptimal contracts (Cockerill, 2006; Shieber, 2009). Improved access to subscription costs can hence be expected to lead to better deals and lower costs for the universities. It can also facilitate transition to the Open Access (OA) publishing model.

Why don't major research institutions systematically publish their subscription fees to scientific journals?

References:

Shieber, S M (2009). Equity for Open-Access Journal Publishing. PLOS Biology 7(8): e1000165.DOI: http://dx.doi.org/10.1371/journal.pbio.1000165
Cockerill, M (2006). The Economics of Open Access Publishing. Information Services and Use 26(2): 151–157. Available at: http://content.iospress.com/articles/information-services-and-use/isu499 [Last accessed 28 October 2015].
Presumably an important reason is that publishers contractually forbid libraries from disclosing this information, see for example http://access.okfn.org/2014/04/24/the-cost-of-academic-publishing/:


  And then libraries are not allowed to tell anyone what these costs are. Libraries are placed under huge amounts of pressure not to release this data, and in the case of Elsevier, they are explicitly forbidden to by non-disclosure agreements in the contracts they have to sign.


This is a reference from 2014, so perhaps meanwhile things have changed (but I would guess not).