This study used time series analysis of 21 years (1970- 1990) of school productivity data from Virginia to demonstrate the usefulness of time series models in describing variations in school input (primarily expenditures) and output (primarily student attainment and achievement) variables. In the study, a series of trend-removed, ARIMA(1,0,0) autoregressive time series models for school input variables were developed to describe long-term trends in school expenditures, instructional salaries and pupil/teacher ratios and to account for year to year variation in levels of school inputs. Residuals from these models for school inputs were correlated with student attainment scores and achievement score residuals with student ability removed to identify those school productivity inputs having the strongest association with school outputs. The scores of input variables having strong associations with school outputs were then plotted over the 1970-90 time period and descriptively related to historical records of legislative and administrative policy decisions thought to have had statewide effects on school productivity in Virginia. The association of school productivity relationship changes with actual policy events was then described. All school input variables could be described with time series accounting for 90+% of the year to year variance in inputs. Time series residuals from expenditures, instructional salaries and pupil/teacher ratio inputs were moderately to strongly associated with two output measures: 1) the percent of Virginia school graduates attending college; and 2) the percent of dropouts, in most Virginia (30 < N < 100) school districts. These inputs shared 20 to 40% of their variance in common with school attainment outputs. School input residuals for local expenditures and pupil/teacher ratio were also strongly associated with reading, math, and language arts achievement residuals in a small number (N=2- 31) of Virginia school districts. Stronger relationships between inputs and achievement scores in greater numbers of Virginia school districts may be revealed when more years of data are available for future analysis. Plots of significant school input variables concurrently with school outputs and historical policy change events suggested that at least three policy change events may have had positive long term effects on school productivity in Virginia from 1970-90. Legislative commitment to a reduction in pupil/teacher ratio in the early 1980's seems to be associated with a long term decrease in dropout rates and increases in college attendance among students in most Virginia school districts. Commitment to higher teacher salaries in the same time period also seems to be associated with positive changes in college attendance and reductions in dropout rates. Finally, the long term expansion of total educational expenditures in Virginia, primarily through adoption of special education, health education, and dropout prevention curriculum initiatives, seems to be associated with rising levels of student promotion rates, percent of ninth grade students graduating and percent of students attending college from 1970-90. / Ph. D.