Abstract
Since Perron (1989) the time series literature has emphasised the importance of testing for structural breaks in typical economic data sets and pronounced the implications of structural breaks when testing for unit root processes. In this paper we survey recent developments in testing for unit roots taking account of possible structural breaks. In doing so we discuss the distinction between taking structural break dates as exogenously determined, an approach initially adopted in the literature, and endogenously testing break dates. That is, we differentiate between testing for breaks when the break date is known and when it is assumed to be unknown. Also important is the distinction between discrete breaks and gradual breaks. Additionally we describe tests for both single and multiple breaks and discuss some of the pitfalls of the latter.
Original language | English |
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Place of Publication | United Kingdom |
Number of pages | 23 |
Publication status | Published - 6 Oct 2006 |
Keywords
- unit root
- structural breaks
- endogenous breaks
- gradual breaks
- multiple breaks