In 2014, Pieper drafted a resolution of the European Parliament calling for more stringent impact assessments before EU legislation is proposed.

The resolution, passed with a large majority, backed an idea set out in the Stoiber ‘red tape report’ – drawn up by a high-level group chaired by Edmund Stoiber, former Minister-President of Bavaria – calling for the creation of a high-level advisory body on better regulation.

[3] In addition to his committee assignments, Pieper has been a member of the European Parliament Intergroup on Biodiversity, Countryside, Hunting and Recreational Fisheries since 2014.

[4] In 2024, Pieper was appointed by the European Commission as EU small and medium-sized enterprises (SME) Envoy, reporting directly to President Ursula von der Leyen and to the European Commissioner for Internal Market Thierry Breton.

[5] His appointment over two qualified women caused "the most serious internal rebellion von der Leyen has faced since she first became head of the EU's executive branch back in 2019", according to Politico.eu.