13) Moreover, Wilson (1980, 1983a, 1983b) notes that the RRCC measure does not seem to be sensitive to the inclusion or exclusion of externalities.
To interpret the RRCC estimate, if the RRCC is greater than zero, then teaching is the preferred occupation and conversely, if the RRCC is negative, it can be considered 'unprofitable' to enter into the chosen occupation.
Chart 8 displays the RRCC measure for male teachers while chart 9 illustrates the results obtained for female teachers.
Our estimated RRCC for both male and female teachers shows a declining trend over the time period of analysis.
While the declining trend in the RRCC to becoming a teacher emulated the RRCC trend found in Wilson (1983a), the absolute RRCC which we obtained is much lower than that obtained by Wilson.
We believe that the higher estimated RRCC in Wilson's paper is due to the broader definition used in estimating the expected earnings stream of alternative occupations for teachers.
The peaks in 1987 and 1993 in the estimated RRCC results for both males and females (more prominent in the RRCC for male teachers) reflect the changes in teacher's pay over the years.