This paper surveys the literature on the impact of investor horizon on corporate policies. While the desire to encourage long-term investor ownership is shared among managers, boards and policy makers, how greater long-term investor ownership benefits corporate decisions and ultimately firm performance is still under academic investigation. The contribution of this paper is twofold. The paper's first contribution is providing an up-to-date review of theoretical and empirical findings. This paper introduces the groups of long-term and short-term investors and the related classification methodologies and investor horizon proxies used to form them. It further reviews the determinants of an investor's horizon. Then, this paper organizes the literature on the impact of investor horizon on corporate policies around three main channels: the short-term pressure hypothesis, the monitoring hypothesis, and the catering hypothesis. The paper's second contribution is identifying six major challenges ahead that need to be addressed to improve the understanding of the impact of long-term (short-term) investor ownership on corporates policies. These challenges represent opportunities for further research.