What does SE stand for?

To attempt this, she evaluated 20 interest rate, money, foreign exchange, unemployment and output measures using the root mean square errors (RMSE) of their inflation forecasts as a criterion and the naive forecast of unchanged inflation as a benchmark.

Murphy then examines the impact of four uncertainty variables: a measure of nominal uncertainty based on the mean square errors of a regression of the inflation rate at the time the contract is signed, a measure of real uncertainty based on the mean square errors of a regression of the unemployment rate, a measure of the uncertainty of the local labor market, and a measure of the uncertainty surrounding the ratio of consumer prices (which matter to workers) and producer prices (which matter to firms).