On Time to the Doctorate -- Copyright -- Preface -- Contents -- Executive Summary -- FINDINGS -- Trends in TTD -- Trends in Components of TTD -- Modeling TTD -- CONCLUSIONS -- 1 What has been Happening to Time to the Doctorate? -- COMPONENTS OF TIME TO THE DOCTORATE AND HOW THEY HAVE CHANGED THROUGH TIME -- The Several Kinds of Time -- Mean Total Time to the Doctorate -- Mean Time Spent Prior to Graduate Entrance -- Mean Registered Time to the Doctorate -- Mean Time Spent Away from the University -- Summary -- THE NATURE AND SIGNIFICANCE OF THE TIME TREND -- The Two Models -- Patterns of Change -- The Shape of Change -- MANPOWER LOSS FROM LENGTHENING TOTAL TIME TO THE DOCTORATE -- 2 Models of the Factors that Affect Student Choice and Time to the Doctorate: A Literature Survey -- LITERATURE ON PERSISTENCE AND ATTRITION -- LITERATURE ON EDUCATIONAL ASPIRATIONS -- LITERATURE ON ENROLLMENTS -- LITERATURE ON EXPECTED RETURNS -- LITERATURE ON TTD -- SUMMARY -- 3 A Model of the Determinants of TTD -- THE MODEL -- THE CRITICAL ROLE OF OPPORTUNITY COSTS -- FINANCIAL AID AND ITS IMPACT ON COMPLETION TIMES -- The Impact of Type of Aid -- Effects on the Components of TTD -- MARKET FORCES AND COMPLETION TIMES -- Effects of Changes in Relative Salaries -- Effects of Employment Opportunities -- Effects on the Components of TTD -- THE VARIABLES USED TO DEVELOP THE MODEL -- 4 The Relationship Between the Five Vectors of Variables and TTD and its Components: A Comparison of Zero-Order Correlations -- THE IMPORTANCE OF DISAGGREGATION BY FIELD -- CHANGES IN FAMILY BACKGROUND CHARACTERISTICS -- CHANGES IN STUDENT ATTRIBUTES -- CHANGES IN TUITION AND FINANCIAL AID -- CHANGES IN INSTITUTIONAL ENVIRONMENT -- CHANGES IN MARKET FORCES -- Salary Variables -- Employment Indicator Variables -- THE STOCK VARIABLE -- THE ZERO-ORDER CORRELATION OF THE VECTORS -- SUMMARY.

5 Changes in TTD -- COMMON VARIABLES MODEL -- Log Linear Equations -- Weaknesses of the Common Variables Model -- UNIQUE VARIABLES MODEL -- SUMMARY OF FINDINGS -- Limitations of the Analysis -- What Can Be Learned from the Findings? -- 6 Changes in Registered Time to the Doctorate, Time Prior to Graduate Entrance, and Time Enrolled in the University -- REGISTERED TIME TO THE DOCTORATE -- RTD in the Common Variables Model Using Linear and Log Linear Equations -- RTD in the Unique Variables Model -- Evaluation of the Results -- TIME SPENT PRIOR TO GRADUATE SCHOOL ENTRANCE (TPGE) -- TIME NOT ENROLLED IN THE UNIVERSITY (TNEU) -- SUMMARY OF THE FINDINGS -- 7 Past as Prologue -- WHAT HAS HAPPENED TO TIME TO THE DOCTORATE? -- Total Time to the Doctorate -- Registered Time to the Doctorate -- Variation Around the Mean -- COULD CHANGES IN TPGE AND TNEU HAVE BEEN LARGE ENOUGH TO EXPLAIN THE CHANGE IN TTD? -- POSSIBLE EXPLANATIONS -- Epistemic Explanations -- Institutional Explanations -- Student Preference-Based Explanations -- Financial Need-Based Explanations -- Demographic and Ability-Based Explanations -- Market-Based Explanations -- Is There A Single Explanation for Increase in TTD? -- IMPLICATIONS OF A CONTINUING RISE IN TTD -- A More Resource-Intensive Doctoral Program -- A Longer Gestation Period -- Increased Attrition -- Lower Returns for Graduate Study -- Changes in the Attractiveness of Alternative Doctorate Careers -- TTD AS A POLICY INSTRUMENT -- Selected Bibliography -- Appendixes -- Appendix B List of Acronyms.