Shadow economic activities constitute a large and growing part of all economic activity throughout the world. Because all individuals engaged in these activities wish not to be identified it is very difficult to get accurate information about the relationship between corruption and shadow...

In recent years, the significant and intensive change of working conditions necessitates employees to modify their work patterns to increase the number of working hours and work intensity by improving the efforts, which leads to the occurrence of the heavy work investment (HWI) phenomenon....