Computes a statistic based on the Lagrange Multiplier (LM) test of Engle (1982) for
autoregressive conditional heteroscedasticity (ARCH). The statistic returned is
the \(R^2\) value of an autoregressive model of order
stat_arch_lm(x, lags = 12, demean = TRUE)
a univariate time series
Number of lags to use in the test
Should data have mean removed before test applied?
A numeric value.