Quarterly U.S. unemployment: cycles, seasons and asymmetries

This paper documents three stylized facts for the quarterly unemployment rate in the United States. Firstly, unemployment is asymmetric over the business cycle, i.e. it rises sharply in recessions and it falls slowly in expansions. Secondly, its seasonal fluctuations are not constant across the two business cycle stages in the sense that there is less seasonality in recession periods. Thirdly, the effect of shocks to the unemployment rate in expansions seem transitory, while this effect is permanent in recessions. Some implications of these stylized facts for empirical macroeconomics and seasonal adjustment are discussed

Is investment time irreversible? Some empirical evidence for disaggregated UK manufacturing data

It has long been suggested that investment may be time irreversible, and consideration of the option value of waiting to invest has aroused renewed interest in this issue. This study tests for time irreversibility in UK investment according to disaggregation by type of investment expenditure and across manufacturing sector groupings. The test results reported indicate that the irreversibility of investment patterns varies not only from industry to industry but also according to the type of capital being purchased, with significant time irreversibility detected in gross fixed capital formation and aggregate vehicles expenditure, and industrial sector groupings comprising fuels and oil refining, engineering and vehicles, and textiles and leather. However, only in the first and last of these series is time irreversibility attributable to non-linearities in the underlying data generating process, and consistent with threshold effects which may be associated with (S,s) type models of investment dynamics.