This paper examines whether `abnormal work practices`, which have rapidly increased since the mid 1990s, are a `bridge` for workers to `normal work practices` or a `trap` from which they are hard to escape. It provides both the static and dynamic analysis. The former shows they are likely to work as a `trap`. The latter, which investigates the transition probability during the last 24 months, also supports the same result. It finds out that most of part-time workers paid by an employer are contingent workers or daily workers and that about fifty percent of `abnormal workers` took them involuntarily.