25 C R I TICAL A CCOUN TING E S TIM ATES AND P OL I C I E S AND C HANG E S I N A CCOU NTING P OL I CI E S I NCL U DING I NITI AL A DOPTI ON IFR S st a nd a r d s i nt e r p r e t a t i on s a nd a me nd men t s t o p u bl ish ed st a nd a r d s wh ich a r e no t ye t effe ct ive I F RS 9 F i na nc ia l I nst r u m ent s IF R S 9 F i n a n c ia l Inst r um e n ts is pa r t of th e I n t e r n a t ion a l A c c ount i n g Sta n da r ds B oa r d s p r oj e c t IAS B t o r e pl a c e I n te r n a tion a l A c c ount i n g Sta n d a r d IAS 3 9 F in a n c i a l Instr um e n ts R e c ogn it ion a n d M e a s ur e m e n t Th e pr o pose d s ta n da r d a ddr e s s e s c l a s s ifi c a tion a n d me a s ur e m e n t of fin a n c ia l a s s e ts a n d r e pl a c e s the mul ti pl e c l a s s ifi c a tion a n d m e a s ure me n t mod e l s i n IA S 39 w ith a s in gl e mod e l tha t ha s on l y tw o c l a s s ifi c a tion c a te g o r ie s a mo r ti z e d c ost a n d fa ir va l ue The c l a s s ifi c a tion a n d m e a s ure m e n t o f fin a n c ia l l ia b il itie s a r e th e s a m e a s p e r IA S 39 b a r r in g tw o a s p e c ts The e ff e c tive da t e of this n e w s ta n da r d is fo r a n n ua l pe r iod s b e gi n n i n g o n or a ft e r J a n ua r y 1 201 5 The C omp a n y is c ur r e n t ly a s s e s s in g th e fin a n c ia l imp a c t of this n e w s ta n da r d S ign ific a n t a ccou n t ing ju d gemen t s a nd est i ma t es M a n a ge m e n t ma k e s va r i ou s e s ti ma te s a n d a s s umpti o n s i n de te r mi n in g the r e p o r te d a m ount s of a s s e ts a n d l ia b il itie s r e v e n u e a n d e xp e n s e s fo r e a c h p e r i od pr e s e n t e d C ha n g e s in th e e s ti ma te s a n d a s s umption s wi l l oc c ur b a s e d on a dd itio n a l in fo r ma tio n a n d the o c c urr e n c e of fu ture e v e n ts a n d a c tua l r e s ul ts c oul d dif f e r f r om thos e e s ti ma te s The mor e s ig n ifi c a n t a r e a s r e q uir in g th e us e of ma n a ge m e n t e s tima t e s a n d a s s umption s r e l a te t o m in e r a l r e s e r v e s tha t a r e th e b a s is of f utu r e c a s h fl ow e s ti ma te s a n d u n it of pr oduc ti on d e p r e c ia tio n de pl e tion a n d a mor tisa ti on c a l c ul a tion s e n vi r o n m e n ta l r e c l a ma tion a n d c l osu r e ob l iga tio n s e s tima t e s of r e c ove r a b l e gol d a n d o the r ma te r ia l s in in c ir c uit in v e n t or y a s s e t i mpa ir me n ts wr it e dow n s of i n v e n t or y t o n e t r e a l i z a b l e va l ue the fa ir va l ue a n d a c c ount i n g t r e a tm e n t of d e r iva tiv e fi n a n c ia l in s tr u me n ts a n d d e f e r r e d in c o me a n d min i n g ta x e s E s tima te s a n d judg e m e n ts a r e c on ti n ua l l y e va l ua te d a n d a r e b a s e d o n his tor ic a l e xp e r ie n c e a n d othe r fa c tor s in c l udi n g e xp e c ta tion s of fu tur e e v e n ts t ha t a r e b e l ie v e d to b e r e a s on a b l e und e r th e c ir c ums ta n c e s The e s tima t e s a n d a s s umpti on s tha t ha ve a s ign i fica n t r isk of c a us in g a ma te r ia l a d jus tme n t to th e c a r r ying a moun ts of a s s e ts a n d l ia b il iti e s wi thi n th e fin a n c ia l pe r io d a r e d isc us s e d b e l ow C a r r yin g v a l u e of p r ope r t y p l a nt a nd equ ip m ent M ob il e a n d o the r e q ui pm e n t a r e de pr e c ia te d ov e r the i r e s tima t e d us e ful l ife of the a s s e t Pr oduc in g pr op e r ti e s a n d m in e de v e l o pme n t a s s e ts a r e a mo r ti z e d us in g the un its of pr o duc tio n me th od wh e r e the min e o pe r a tin g pl a n c a l l s for pr o duc tio n f r om pr ove n a n d pr ob a b l e m in e r a l r e s e r ve s The c a l c ul a tion of the u n its of pr oduc t ion r a te o f a mor t i z a tion c oul d b e imp a c t e d to the e xte n t tha t a c tua l pr oduc tion i n the fut ure is di ff e r e n t f r om c u r r e n t for e c a s t pr oduc ti on b a s e d on pr ove n a n d pr o b a b l e m in e r a l r e s e r v e s This wo ul d ge n e r a l l y r e s ul t fr om th e e xt e n t tha t th e r e a r e s ig n ifi c a n t c ha n ge s in a n y of th e fa c tor s or a s s umptio n s us e d in e s ti ma tin g m in e r a l r e s e r ve s Th e s e fa c to r s c oul d in c l ude C ha n ge i n pr ov e n a n d pr ob a b l e m in e r a l r e s e r v e s Diff e r e n c e s b e t we e n a c tua l gol d pr ic e s a n d gol d pr ic e a s s umptio n s Unfo r e s e e n o pe r a tio n a l iss ue s C ha n ge s i n c a pit a l o pe r a ti n g m in i n g pr oc e s s in g a n d r e c l a ma tio n c osts d isc ount r a te s a n d for e ign e xc h a n ge r a t e s a n d C ha n ge s i n m in e r a l r e s e r v e s c oul d s imil a r l y i mpa c t th e us e ful l ive s of a s s e ts d e p r e c ia t e d on a s tr a ight l in e b a s is w h e r e th ose l ive s a r e l imit e d to the l i f e of mi n e