To help overcome the difficulty of information overload, we conducted simulations to show the importance of information infrastructure in decision-making. Using simulations based on a NK-model, we show that it makes a difference in results whether decision-makers has a complete information infrastructure. Comparing results from two simulations with or without a complete information infrastructure, we find that the attention structure with a complete information infrastructure is significantly better. We then discuss the issue of developing a complete information infrastructure with some real-world examples.