Page 6 Results
Experience
Overall, doctorate-level income was 37% higher than that of master’s level respondents (t = 8.0, df = 953.1,
p < .001)
3
. Beyond educational attainment, work experience has a substantial impact on I-Os’ income. Time
since degree represents work experience and skill acquisition, both of which are associated with higher
earning potential. Tables 1 and 2 show median and mean salary along with percentile distributions for
doctorate-level and master’s-level members by years since highest degree earned.
Unlike in past reports, the income trajectory for doctorate-level I-Os did not consistently increase with years
since degree. Notably, salary percentiles for the 20-to-24-years group are slightly inflated compared to their
adjacent cohorts, suggesting that this cohort contains some extremely high incomes. Salaries for the 15-to-19-
years cohort at or below the 50
th
percentile are slightly deflated compared to the 10-to-14-years cohort. To
better understand the trends in median income, we examined additional characteristics of doctorate holders for
those at 15-to-19 years since degree and those at 25-or-more years since degree. In the 15-to19-years cohort,
the median salary for men ($150,559) and women ($146,694) were both close to the overall median. Within
the 25-or-more-years cohort, the median salary was $196,500 for men and $153,562 for women (although this
difference was not statistically significant), with women making up about 41% of this cohort. In the remaining
cohorts, median salaries for men and for women were similar, with median salaries for women being higher
than for men in the 5-to-9-years, 10-to-14-years, and 20-to-24-years cohorts. The gender effect for the 25-or-
more years cohort may contribute to the relatively lower salaries in the 25-or-more-years since degree group.
Gender differences in pay are discussed in more detail in a later section of the report.
Table 1. Base Salary by Years Since Doctorate Degree
Years Since Degree
< 2 2-4 5-9 10-14 15-19 20-24 25+
n 25 107 157 87 71 57 99
Median $100,000 $110,000 $130,000 $150,000 $149,000 $190,000 $160,000
Mean $109,214 $119,192 $142,950 $168,021 $172,158 $278,667 $217,747
Percentile
90th $142,400 $170,200 $212,000 $225,000 $245,000 $320,938 $300,000
75th $124,000 $137,500 $165,000 $184,500 $198,000 $240,000 $232,000
50th $100,000 $110,000 $130,000 $150,000 $149,000 $190,000 $160,000
25th $87,500 $95,000 $104,000 $121,500 $118,500 $133,484 $110,250
10th $80,372 $72,900 $85,000 $83,471 $83,300 $91,872 $90,914
3
Welch t-tests were used in cases where group sizes and/or group variances were unequal. The Welch t-test estimates
degrees of freedom using a formula that includes group variance divided by group size, leading to the potential for estimated
degrees of freedom to include decimal places.