We propose an Adjusted Quasi-Score (AQS) method for constructing tests for homoskedasticity in spatial econometric models. We first obtain an AQS function by adjusting the score-type function from the given model to achieve unbiasedness, and then develop an Outer-Product-of-Martingale-Difference...

This paper proposes a test for sphericity in a fixed effects panel data model. It uses the Random Matrix Theory based approach of Ledoit and Wolf (2002) to test for sphericity of the error terms in a fixed effects panel model with a large number of cross-sectional units and time series...

This paper investigates the propagation of instability through key asset markets of the US financial system - equity, real estate, banking and treasury - between 1/3/2000 and 12/26/2014. For this purpose, we develop an identification method to uncover characteristic financial market...