可以

首先谢谢您！如果有解释说明的话，那就更感激！

我觉得嘛 你可以把被解释变量和那两个解释变量分别画图 看一下所谓的unconditional correlation是什么样的 直观地去观察你的数据 再去思考变化的原因是什么 这样可能在写文字阐述时会更加有理有据

if only using the two variables as independent variables, we can think the B (coefficient vector) based on all sample is a weighted average of B1 and B2 based on samples from 00-05 and 06-10, as an approximation, if B2 is not significant, then B depends on B1

firstly, thank you ! if there are many variables including the above two critical explained ones and other controlled variables , but for B1,two critical explained variables are negatively significant ,for B2, they are nonsignificantly positive.Besides, there are not obviously different in other controled variables at two periods. therefore, can i conclude that according to my understanding of what you said, the negatively significance of  two critical explained variables in B depends on B1.As i am not good at english ,i explain  simple question into complicated one. i hope you can understand what i mean. thank you!