Professional roles and professional knowledge  It is naïve to assume- as side proposition do in their opening argument- that standards of innovation, knowledge and insight will improve within a business simply because it is compelled to hire younger workers. This is especially true of the professions – jobs and businesses that service pressing social needs tightly regulate the knowledge and conduct of their members and, typically, require them to continually maintain, revise and update their knowledge and skills.  In many professional roles expertise and mastery of the skills underlying the job itself take an unavoidably long time to achieve. Judges in the UK have to have held legal qualifications for five to seven years, [i] consulting physicians for which it takes twelve years to get the relevant qualifications and training, [ii] architects and master craftsmen are all as much a product of experience and practice as they are education and investment. Implicit in the cost advantage of hiring a young professional is the knowledge that they will have to work under the supervision and tutelage of older colleagues for most of their lives. Professionals are also a product of knowledge sharing and mentorship.  Put simply, arbitrarily using age to exclude older professionals from their fields of expertise will have a material impact upon the training and development of younger professionals. Western liberal democracies’ professional classes are based partly on communitarian principles of a carefully curated shared culture. Removing senior practitioners in law, medicine and civil administration severs a link with the collective knowledge of that professional culture – a link that cannot easily be replicated in the classroom environment.  [i] “Becoming a Judge”, Judiciary of England and Wales,   [ii] “The length of training involved in becoming a doctor”, Medical Careers,