doc: spatial lag impacts

[JosiahParry]

Hi team! I'm quite interested in the release notes at https://github.com/pysal/pysal/releases/tag/v24.07 which mention the calculation of impacts in spatial lag model estimation.

There aren't any citations in the GM_lag method docs or that I could find in the PR https://github.com/pysal/spreg/pull/145/files.

Are you all able to point to which papers' are implemented in the impact calculations? I'd quite like to read up on it!

Thanks :)

[pedrovma]

Hi @JosiahParry ! The impacts literature used is cited here:
https://github.com/pysal/spreg/blob/aeb34f18aa1f2586c14ffa2f2673f48f56e4de87/spreg/sputils.py#L283C5-L283C94

For the Simple method:

• Kim, C. W., Phipps, T. T., & Anselin, L. (2003). Measuring the benefits of air quality improvement: A spatial hedonic approach. Journal of Environmental Economics and Management, 45(1), 24-39. https://doi.org/10.1016/S0095-0696(02)00013-X

For Power and Full methods:

• LeSage, J., & Pace, R.K. (2009). Introduction to Spatial Econometrics (1st ed.). Chapman and Hall/CRC. https://doi.org/10.1201/9781420064254

Best,

Pedro.

[JosiahParry]

Thanks, @pedrovma! The docs say

spat_impactsstr
Include average direct impact (ADI), average indirect impact (AII),
and average total impact (ATI) in summary results. Options are ‘simple’, ‘full’, ‘power’, or None. See sputils.spmultiplier for more information.

However there isn't any public documentation for the sputils module. So the documentation for it is not discoverable.