Fig. 3

Chronological order of partial correlation coefficients. This figure shows the chronological order of partial correlation coefficients of estimates of the gender dummy variable reported in 53 research works listed in Additional file 1: Table S1 and Additional file 2: Bibliography of studies subject to meta-analysis. See Table 1 for the descriptive statistics of estimates. The solid black line in the figure displays the fit line. The equation of the fit line is described below. The values in parentheses below the coefficients in the equation are robustness standard errors. *** denotes statistical significance at the 1% level. r = -13.3680(1.1291)^*** + 0.0066(0.0006)^***yr. Adj. R² = 0.1685 F = 136.55^***