NOMINAL RIGIDITIES VERSUS REAL RIGIDITIES  

Nominal rigidities are said to exist when nominal prices and wages  do  not change in  the  face  of  conditions that call for their change. As  you  have seen  in  earlier units,  this  will lead  to  Keynesian unemployment. But unemployment can also come about because of certain real rigidities in  the  economy.  Such  rigidities  can  exist in  the  goods market,  the labour market or even the market for credit. 

There could exist reasons why  the real wage paid  in the labour market  is higher than the market-clearing wage. This will, of course, lead  to unemployment of  some of those who are willing  to work  at a lower (market-clearing) wage. We are not talking here about the nominal wage not changing when it needs to change, but about firms rationally and voluntarily deciding to pay higher real wages to their workforce because they find it to their advantage  in  some way. We will  explain  this  concept  of  real rigidities  better when we list out all such rigidities in Section 15.5 and the sub-sections therein. The New Keynesian economists stress both  the nominal and real rigidities  to explain the presence  of booms  and  bust/  persistent unemployment in the real world.