1.The measure of income inequality, Gini coefficient, is statistically significant in all five specifications under OLS, but it is only marginally significant (p < 0.10).

2.Further, the greatest proportion of the variation in income mobility is explained by the specification that includes both the Gini coefficient and corruption in column (2) with an adjusted R2 of 0.53.

3.Column (3) is the only other alternative specification that exhibits a statistically significant influence on intergenerational earnings elasticity, but the positive relationship between rule of law and intergenerational earnings elasticity is only marginally significant with a t-statistic of 1.95.

这是一篇阐述制度如何帮助摆脱盖茨比曲线的文章，文章采用了计量方法。请问specification是什么意思，这几个句子里的specification都是一个意思吗