有点贵，能降价么

很抱歉，暂时还没打算降价

大家去谷歌学术下载吧。这是篇论文。可以不用花论坛币购买。前车之鉴。

可以简单介绍一下不？

Regression Discontinuity Designs
in Economics
David S. Lee and Thomas Lemieux*
This paper provides an introduction and “user guide” to Regression Discontinuity
(RD) designs for empirical researchers. It presents the basic theory behind the research
design, details when RD is likely to be valid or invalid given economic incentives,
explains why it is considered a “quasi-experimental” design, and summarizes different
ways (with their advantages and disadvantages) of estimating RD designs and
the limitations of interpreting these estimates. Concepts are discussed using examples
drawn from the growing body of empirical research using RD. ( JEL C21, C31)