----------------- HES POSTING ----------------- 
 
First, isn’t this question of full (or perfect) information to do with  
formalization? To get hard-edged results (even to make problems  
tractable at all) takes simplifying assumptions - full information,  
divisibility, continuity of preferences, etc. Classical profit rate  
equalization requires full information about potential profitability in  
different sectors. We all know these are approximations. On a less  
formal level it can be fudged (as Marshall did) but formalization  
brings out the implicit assumptions.   
 
Second, full information about what? Depends what is being  
modelled. Basic perfect competition (demand and supply) requires  
full information about prices offered, but not much else. Simple  
intertemporal choice models require the individual to act as if she  
had full knowledge of the future, etc.   
 
Third, the full information assumption has been systematically  
relaxed in modern mainstream economics - asymmetric  
information is a major theme now, because we have figured out  
how to model incomplete information and found that it gives useful  
insights.   
 
Tony Brewer 
University of Bristol 
 
------------ FOOTER TO HES POSTING ------------ 
For information, send the message "info HES" to [log in to unmask]