Kai-Jie Wu received his PhD in economics from the University of Rochester. His research focuses on macroeconomics, economic growth, and labor economics. Kai-Jie has studied the role of specialized firms as a driver of increased industry concentration over the last 40 years. Specialized firms, which produce higher quality goods, have replaced diversified firms over time and this can explain the entire increase in industry concentration over the period. Earlier this year, this research was discussed in. the Economist. We welcome Kai-Jie to Penn State.