AKM: statistical tests

[adamoppenheimer]

Add statistical tests for AKM, e.g. from:

• AMS - endogenous mobility

• DJ - non-stationarity of parameters

• BLM - identification of interacted BLM

• SLM - endogenous mobility

[adamoppenheimer]

Sancibrián - non-stationarity of parameters

[adamoppenheimer]

LMSW - they evalaute non-stationarity of parameters, I'm not sure if they actually have a statistical test for it though

[adamoppenheimer]

Wong - Appendix B.2 has some exogenous mobility and log-additivity robustness tests

[adamoppenheimer]

ABEM - log-additivity and exogenous mobility CGLS - log-additivity and exogenous mobility

[adamoppenheimer]

GR - log-additivity and exogenous mobility