尤其是最后半句这个“under which”，确实不知道在此处是什么结构。
Comparisons help us to gain a better understanding of certain features of an object of analysis. For example, if we are interested in the justice implications of a policy instrument, we can compare how the same policy instrument is implemented in two different countries, and draw conclusions on the conditions under which the policy instrument does not increase injustice.
1. 首先，有关under which是什么结构的问题涉及一种重要的语法现象：由“介词+关系代词”引导的定语从句。题主只要耐心认真看懂下面的两个个例子就清楚了。
①“我们需要能给我们带来益处的帮助”这句话，英语可以先说“我们需要帮助”We deed help.，然后再把是什么样的帮助附在后面，作为help的定语从句。
“我们能从帮助中获益”的英语是We can benefit from the help.将这句话变成help的定语从句有两种方式：
一是把the help变成which提前至句首---which we can benefit from，此时整个句子“我们需要能给我们带来益处的帮助”就成了
We need help which we can benefit from.
二是把介词from连同the help变成which后的整个部分from which提前至句首---from which we can benefit.，此时整个句子变成
We need help from which we can benefit.
②句子“我们想要一位能一起工作好的人”的英语译文包括两块：第一块是“我们想要一个人”We want a person.；第二块“能一起工作好的”则要用定语从句的形式表达，而这要从句子“我们能和他一起工作好”
We can work well with him.
变换而来。依然是两种方式：
一是把him变成whom放到句首---whom we can work well with.
另一是把him变成whom后连同前面的with一起提前至句首---with whom we can work well.
整个句子“我们想要能一起工作好的人”当然也有两种表达：
We want a perso whom we can work well with.
We want a person with whom we can work well.
2. 更多“介词+关系代词”引导定语从句的例：
①The girl slapped the man whom Mr. Smith is talking to.=The girl slapped the man to whom Mr. Smith is talking.（姑娘掌掴了史密斯先生正与之说话的那个男人。）
② The people to whom the government provided emergency supplies were desperate.=The people whom the government provided emergency supplies to were desperate.（政府提供给紧急援助的那些人急需救援。）
③This is the plan which we discussed about at the meeting.=This is the plan about which we discussed at the meeting.
3. 关于题主这段文字的译文，楼上答主已经给出，恕不再赘述。