Figure A9.
The image features two scatter plots depicting regression discontinuity analyses for electrical work bids. The left plot shows the relationship between bid price ratio and the proportion of winning bids in general competitive bidding, with a polynomial fit line applied to the data points represented by grey dots. Key annotations include the regression discontinuity value of negative zero point zero four seven and a z-score of negative zero point four nine two. The right plot presents a similar analysis for designated bidding, with data points also indicated in grey and a polynomial fit line. This graph indicates a regression discontinuity of negative zero point zero seven nine and a z-score of negative zero point seven zero one. The X-axis in both plots represents the bid price ratio, while the Y-axis denotes the proportion of winning bids. Each plot includes the label "Sample average within bin" for clarification on data representation within each bin.Electrical work procured by Ehime Prefecture
Note(s): The graph, generated using the rdplot command in Stata, illustrates the regression discontinuity (RD) analysis, displaying estimated discontinuities and fitted lines. A second-order polynomial is used for visual approximation, whereas the discontinuity and corresponding z-value at the top of each panel are estimated using a linear model within the selected bandwidth
Source: Author’s own work