Recognition that welfare states continue to change has fostered debate about the relationship between ideas and policy problems in driving governments towards reform. To move the debate forward, this article proposes a modification of Barbara Vis and Kees van Kersbergen's 'open functional approach'. It first argues that while policy problems may provide 'functional pressure' to reform, this pressure is significant only in so far as inaction would risk electoral punishment. Reform pressure is hence best evaluated with reference to contemporaneous expert advice, public opinion data and the timing of elite and media attention. Second, it suggests that ideas may also lead parties to act as reform seekers, using policy problems as justification for cherished solutions or long-held programmatic goals. The modified approach is demonstrated through comparative application to two case studies, attempts at pension reform in Sweden and the United States.