For research highlighting potential alternative interpretations, see Michael T. Kiley (2014), “An Evaluation of the Inflationary Pressure Associated with Short- and Long-Term Unemployment (PDF)”, Finance and Economics Discussion Series 2014–28 (Washington: Board of Governors of the Federal Reserve System, March); and Christopher Smith (2014), “The Effect of Labor Slack on Wages: Evidence from State-Level Relationships”, FEDS Notes (Washington: Board of Governors of the Federal Reserve System, June 2).
This apparent preference for equities is, however, only a partial explanation at best. Australian superannuation funds do hold a large portfolio of fixed-income securities. However, within this portfolio, there are just not many fixed-income securities issued by the corporate sector.