802                                                    23

   $100,      
$2200 [(100  $23) - $100].      10% [($2200 -
- $2000)/$2000],         21,65% [(2300 - $1900)/
/$1900].   .

23.3.3     

       -
 ,      (  ).  
  . ,     ,
    .      , 
          ,  
          . 
    ,      -
.  ,         
      .    -
       ,    
          -
  ,    , -
          
 .    ,    -
      ,   -
 ,          .

23.3.4    

   ,    , :   -
 ,          -
  . ,     -
 ,      , 
  (,  ),      .  -
,       ,     
 .      .

  ,  ,  , -
      ,      -
  . ,   ,   -
        t  1    
  t.       :

SPt=a+bM,_^,                          (23.2)

 SPi     S&P 500    t; ^ _,  -
      t  1;   b   .  
   S&P 500       
    .

    ,    -
   .    ,     -
    1985  1994 .  ,    
   1994 .      -
   ,        1985