Policy specialisation in the twenty-first century UK House of Commons

We provide the first systematic analysis of policy specialism in the UK Parliament for nearly two generations through the development of a novel, multifaceted classification of specialisation/generalisation. We detail patterns of specialism and generalism among all backbenchers who sat in the House of Commons between 2001 and 2019 (<i>n</i>=1,295) by using topic modelling and k-means clustering to analyse five areas of parliamentary activity where specialism/generalism may best be demonstrated. We identify five different groupings – <i>Generalists, Specialists, Semi-Specialists, Active Generalists</i> and <i>Indeterminates</i> – the balance between which suggests that, as found in the 1970s, generalism remains the norm.