This study examines the effect of social capital on analyst forecast accuracy. Using a county-level measure of social capital, I find that firms headquartered in counties with high social capital have greater forecast accuracy than firms headquartered in low social capital counties. In addition, I conduct two cross-sectional tests under conditions where social capital facilitates analyst forecast information collection and where social capital provides more assurance of information reliability. I find that the effect of social capital is more pronounced when firms' headquarters are close to analyst brokerage firms. This is because geographically proximate analysts may have more channels to collect information. I also show that since high social capital can reduce analysts' time and effort to verify the reported earnings when a firm has complicated operation, effect of social capital is more pronounced when a firm's operation is complex. I also find that investors react more strongly to analyst forecast for firms headquartered in counties with low social capital, suggesting that the analyst's role as an information intermediary is more valuable in this setting. Additionally, I employ the relocation of firms headquarters to better establish causality. The results are robust to regional fixed effect, accounting quality, management guidance, analyst fixed effect, and alternative measure of social capital. In sum, these findings suggest that social capital is an important factor that affects analysts forecast accuracy and informativenesss. v Acknowledgments I would like to express my greatest gratitude to everyone who supported me throughout my time at The City University of New York. First and foremost I would like to thank the co-chairs of my dissertation committee: Professor Carol Marquardt and Professor Rong Huang for their valuable guidance, encouragement, and kindness during my doctoral studies. They set excellent examples as successful professors and prolific researchers which would inspire me in my whole career. I am also grateful for my dissertation committee members: Professor Min Shen and Professor Lin Peng. The dissertation would have been impossible for their suggestive comments and insights. In addition to my committee, I would also like to thank faculty and staff in Accounting Department at Baruch College for providing a knowledgeable, supportive, and constructive work environment. Without the tremendous time and effort they devote to doctoral program, I would not make all the progress during my doctoral studies. Their willingness and availability of working with doctoral students witness every step of my progress on conducting research, improving teaching skills, and developing academic personnel. A very special thank you to my coauthors in all the other research projects for their enormous and valuable inspiration, endeavor, and support. I am also thankful to my fellow doctoral students and previous cohorts for their friendship, help, and collaborative discussions of research issues. Last but not leas...