Tjarda specialises in EU and Dutch competition law and the regulation of network industries. Tjarda has previously worked at the Dutch Competition Authority, where he focused mainly on competition law enforcement and merger control in the telecom, energy and media sectors. In September 2014, he successfully defended his PhD at Leiden University on the concept of ‘objective justification’ of the abuse of dominance. Tjarda has published in international journals such as the Common Market Law Review, World Competition, European Competition Journal and European Competition Law Review.