Economic Policy covers the aims and the instruments of state economic interventionism. As a broad problematique it existed from the very birth of the science of the economy. However, as a special subject-area it was inaugurated in the interwar era and formalized by the beginning of the post-World War II era. Since then, Economic Policy faced serious ups and lows within economic analysis and policymaking. Particularly within Mainstream Economics (the nowadays dominant tradition within the science of the economy), Economic Policy – and especially its ‘hard’ versions of active fiscal policy, discreet industrial policy and planification – moved from the initial highs of the interwar and Keynesian era to the lows of the Neoliberal period. During the latter Economic Policy was dehydrated from crucial tools and downgraded as a subject because it was castigated as prone to labour demands and popular concessions that suppressed capital’s profitability. Since the beginning of the 21st century – and as a result of the blatant failures of the Neoliberal deregulationist movement – a return of active Economic Policy is on the cards. However, this return within Mainstream Economics is both belated and very problematic. The contemporary orthodoxy of New Keynesianism attempts rather ineffectively to marry an activist economic policy with its neo-conservative insulation from popular pressures for better wages and working conditions. This paper analyses the adventures of Economic Policy within Mainstream Economics from the standpoint of Marxist Political Economy.