From 1970 to 2010, the number of non-teaching staff in the United States (those employed by school systems but not serving as classroom teachers) grew by 130 percent. Today, non-teachers comprise a robust half of the public-school workforce (totaling roughly three million individuals), and their salaries and benefits absorb one-quarter of current education expenditures. Even as states and communities face inordinate budgetary stress, the increase in the numbers of non-teachers has attracted very little attention. This report delves into several data sets to better understand how school staffing has changed over the last half-century. The aim is not to determine whether these changes are "good" or "bad," but to document the changes so that decision makers begin asking better questions about these trends--and in so doing, also do better both by their students and their bottom line. The study resulted in five key findings: (1) Since 1950, school staffing has increased nearly 400 percent, and non-teaching personnel have played a major part in that growth; (2) The United States spends far more on non-teaching staff (as a percentage of education spending) than do most of our economic peers in the OECD; (3) States are far from homogeneous in how their schools are staffed, but much of that variation is due to differences "within" their borders; (4) Over the last forty years, the biggest driver of growth in non-teachers has been in the teacher-aide category; and (5) School districts vary greatly relative to their number of employed personnel, but those differences likely stem from staffing decisions made by leaders. Based on these findings, and drawing on previous research, recommendations for district leaders regarding staffing policies include: (1) Know both the expanse and limits of the authority provided to them via state, district, and local policies; (2) Be creative when solving staffing needs; and (3) Evaluate the necessity--and cost benefit--of hiring additional staff members versus reorganizing existing ones or adopting other solutions. The following are appended: (1) Sources and Methods; (2) Data Used to Calculate Non-Teaching Ratios for States; (3) Calculating Non-Teaching Personnel (Example); (4) Non-Teaching Staff-to-Student Ratio (2010); (5) Aide-to-Student Ratio (2010); (6) Change in Non-Teaching Staff-to-Student Ratio (2000-2009); (7) Change in Aide-to-Student Ratio (2000-2009); (8) Number of Personnel per 1,000 Students, by Urbanicity; and (9) Position Glossary. [Foreword by Chester E. Finn, Jr.]