Treatment of statistical confidentiality Part 5: Rules versus principles Introductory course Trainer: Felix Ritchie CONTRACTOR IS ACTING UNDER A FRAMEWORK CONTRACT CONCLUDED WITH THE COMMISSION

Rules vs principles Two ways of looking at disclosure control ‘rules-based’ Following a set of agreed rules/procedures/tests etc ‘principles-based’ Using the rules as handy rule-of-thumb, but allowing for complete flexibility How computers think How humans think Having spent one and a half days discussing rules for release, but also emphasising the need for judgement and expertise, we now turn to discuss how rigidly we apply these rules – what is the scope for judgment, and where is obedience to rules more important? In this section, we will consider two different views of the world: ‚rules-based‘ versus ‚principles-based‘. This has a particular meaning in the context of output SDC, but we will discuss generallytobring together a number of the themes of the course. The remainder of the slides give a simplified summary of the topics. You are not required to know this; however, studying this topic might help your understanding of the limits within which you work – in particular, the uncertainties that surround your choices. Hence, this is why we use it to provide a summary of the course. If it helps, you can think of this as ‘how computers think’ and ‘how humans think’

A rule… Consider setting a 50km/h speed limit for all roads in towns in Europe advantages? disadvantages?

Advantages Clear and memorable Simple Easy to enforce Consistent in a range of settings Fair

Disadvantages Not appropriate for every context Too low in some cases=>inefficient Too high in some case=>unsafe May not have credibility

A principle… Consider 50km/h as the default, but with towns able to vary depending on context advantages? disadvantages? The hard rule is now a ‘rule of thumb’ to help home in on the specific rule in a specific case

Advantages Responsive to circumstances More efficient Safer Likely to have more public acceptability

Disadvantages Need to notify More complicated to explain More complicated to enforce Demands more engagement from everyone

Principles- versus rules-based What have we been learning? ‘Five safes’ and ‘safe statistics’ emphasis on judgment, experience and evidence Tables and microdata following hard rules and using technical measures We’ve used rules for teaching purposes but the message is: remember the principles humans are good at this computers are good at this When looking at table protection, for example, we’ve looked at simple rules like ‘no singletons’. This is easier for us to discuss in class, but why should we blindly follow this? We decided that the singleton representing hospital management (Table 5) was acceptable. Rules are good – particularly for teaching - but principles are even better. And if it is a job for a computer, use a computer!

Rules and principles Hard rules good when limited and very similar set of contexts transparency highly rated limited chance to engage with others Principles and rules-of-thumb better when circumstances very variable efficiency important able to engage in conversation with other parties Which is better for Eurostat?

European statistics: rules-based or principles-based? rules-based – because all MSs do this for their standard outputs Commission can set specific rules after negotiation with MSs – operational efficiency but keep in mind the principles: not all outputs are equally important exceptions are specific to the context, justifiable from first principles, and worth the effort expert judgement is better than a rule Having said that, we need to face reality, which is you trying to reconcile the views of 28 MSs with finite resources. If the rules are ‚good enough‘, that has advnatages in terms of clarity and consistency Just keep in mind that it is the principles that matter. Also, not all ‚rules‘ are well-founded – they may be a result of history, accident, excessive caution etc, and challenging them may help the MSs as well as you.

References Importance of the right perspective: Ritchie F. (2014) “Access to sensitive data: satisfying objectives, not constraints” Rules versus principles: Ritchie F. and Elliot M. (2015) “Principles- versus rules-based output statistical disclosure control in remote access environments”, IASSIST QUARTERLY, forthcoming Ritchie F. (2014) "Access to sensitive data: satisfying objectives, not constraints", J. Official Statistics v30:3 pp533-545, September. DOI: 10.2478/jos-2014-003 http://www.degruyter.com/view/j/jos.2014.30.issue-3/jos-2014-0033/jos-2014-0033.xml?format=INT Ritchie F. and Elliot M. (2015) “Principles- versus rules-based output statistical disclosure control in remote access environments”, IASSIST Quarterly, forthcoming (working paper available at http://www2.uwe.ac.uk/faculties/BBS/BUS/Research/Economics%20Papers%202015/1501.pdf

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