This semiannual journal provides research and analysis to promote effective policies and programs for children.Contents include: -What Is the Problem? The Challenge of Providing Effective Teachers for All Children Richard Murnane and Jennifer Steele- The Effect of Certification and Preparation on Teacher Quality Donald Boyd, Daniel Goldhaber, Hamilton Lankford, and James Wyckoff- Teacher Wages and Working Conditions Eric Hanushek and Steven Rivkin-Using Performance-Based Pay to Improve the Quality of Teachers Victor Lavy- Learning in the Teaching Workforce Heather Hill- The Challenges of Staffing Urban Schools Brian Jacob- Recruiting and Retaining Quality Teachers in Rural Areas David Monk- Teacher Unions and Student Performance: Help or Hindrance Randall Eberts- Teacher Labor Markets in Developed Countries Helen (Sunny) Ladd- Teacher Labor Markets in Developing Countries Emiliana Vegas