[social mobility lecture] markov chain + shorrocks mobility

[shlff]

As discussed with @jstac we could combine the Shorrocks mobility with the Markov matrix (intergenerational mobility matrix).

See references:

• https://quanteconpy.readthedocs.io/en/latest/tools/inequality.html#quantecon.inequality.shorrocks_index
• https://www.aeaweb.org/articles?id=10.1257/aer.20151684
• https://github.com/jstac/macro_dynamics_text/blob/852052db716a0d68e32bdb871619c69e5635192f/ch_risk.tex#L142

[jstac]

Jet paper on social mobility
dardanoni-jet-93.pdf

[jstac]

Inequality vs social mobility:

https://www.bristol.ac.uk/media-library/sites/cmpo/migrated/documents/wp206.pdf