А С ' Т Л U N I V E R S I T A T I S L O D Z I E N S I S ________ P O L IA O E C O N O M IC A 198, 2 0 0 6
Michał Przybyliński*
IM P OR T SH A R E EQ UATIONS FOR IMPEC
I. I N T R O D U C T I O N
I m p o r t e q u a t i o n s in P o lish m o d e l I M P E C , like in m o s t o f I N F O R U M m o d e ls , e x p l a in th e ratio o f im p o rt to total output. T h a t is w h y , the p r o d u c t c l a s s i fi c a t io n o f im p o r t d a ta m u s t b e the s a m e as in the m o d e l, that m e a n s N A C E . W e c a n not u se S I T C o r P o lish C N d a ta o n im p o r ts s im p ly b e c a u s e they d o n ’t fit to th e d a ta on o u tp u t. At the m o m e n t , o u r d a t a se t in 57 N A C E c la ssific a tio n , c o v e r s 5 y e a r s, a n d th e s e d a t a a r e e x p r e s s e d o n ly in c u r re n t prices, w ith n o i n f o r m a ti o n a b o u t p ric e defla to rs. T h e m o s t d e t a il e d tim e series w e c a n c o lle c t n o w i n c lu d e 10 c a te g o rie s a c c o r d i n g to N A C E . T h e d a t a c o v e r t h e p er io d 1 9 8 4 - 2 0 0 1 .
T h e p r e v i o u s v e r s io n o f im p o r t s h a r e e q u a t i o n s ( P r z y b y l i ń s k i 1998) w a s v e ry m o d e s t, as th e c o m m o d i t i e s w e r e d i v i d e d in to th r e e g r o u p s o n ly .
P ra ctically , th e re is n o i n f o r m a ti o n a v a ila b le o n im p o r t o f se rv ic e s . It m i g h t b e ca lc u la te d b y s u b tr a c tin g c o m m o d i t y im p o r t f ro m im p o r t in N a ti o n a l A c c o u n ts , bu t e v e n this o p e r a tio n is not p re c is e - s o m e t i m e s w e get n e g a t i v e values.
F o r th e p u r p o s e s o f I M P E C tw o s e ts o f e q u a t i o n s w e r e e s t i m a t e d . T h e first set o f s y m p t o m a t i c ( t i m e tr e n d ) e q u a t i o n s s h o w s th e p a t t e r n s o f t r a n s i t i o n in e a c h g r o u p o f c o m m o d i t i e s . T h e m a i n ide a h e r e is to s h o w th e e x p e c t e d g r o w t h in im p o r t s h a r e s , d u e to o p e n i n g th e e c o n o m y . A n o t h e r s e t o f e q u a t i o n s u se s s o m e e x p l a n a t o r y v a r ia b le s . It s h o u l d s e r v e fo r s i m u l a t i o n s , w h e r e c h a n g e s in p r ic e s o r e x c h a n g e r a te s a re c o n s id e r e d . II. T R A N S I T I O N C U R V E T h e o p e n i n g o f P o lis h fo re ig n tr a d e s ta rte d in 1990, a l t h o u g h s o m e s te p s t o w a r d s it c a n b e s e e n in la te eig h tie s. S o o n a f te r th e fall o f t h e c e n t r a l l y p l a n n e d e c o n o m y a n d C O M E C O N , r e g u l a t i o n s in P o lish f o r e ig n t r a d e g r a d u a l l y c h a n g e d t o w a r d s the f u t u r e j o i n i n g th e EU. Until 2001 th e v o l u m e , a s w e ll a s v a l u e c a l c u la ted in U S D o f c o m m o d i t y im p o r t s in c re a s e d m o r e t h a n fiv e t i m e s c o m p a r i n g to 1990. A c c o r d i n g to N a ti o n a l A c c o u n t s , th e v o l u m e o f i m p o r t s o f g o o d s a n d s e r v ic e s in c r e a s e d b y o v e r f o u r tim es.
Chair o f Theory and Analyses o f Economic Systems. University o f Łódź [159]
S i m i l a r t c n d c n c i e s a r e s h o w n in e x p o r t , b u t th e r is e is n o t so h ig h . T h e c h a n g e s in r e la t i v e p r ic e s o f e x p o r t h a s b e e n m o r e d y n a m i c , s o w e c a n s e e that t h e s h a r e o f e x p o r t in G D P h a s r is e n s ig n i f i c a n t l y in th e n i n e tie s , o n l y i f w e c a l c u l a t e it in c o n s t a n t p r ic e s . T h i s s h a re in c u r r e n t p r ic c s s e e m s r a t h e r s ta b le . A p a r t f r o m t h e c h a n g e s in r e g u l a t i o n s to w a r d s free m a r k e t a n d o p e n i n g o f t h e e c o n o m y , t h e r e is p r o b a b l y a n o t h e r t e n d e n c y h id d e n h e r e , w h i c h h a s m o r e u n i v e rs a l ro o ts. T h i s is t h e g l o b a l t e n d e n c y t o i n c re a s e th e t r a d e t u r n o v e r c a u s e d b y m o r e e f f e c t i v e m e a n s o f c o m m u n i c a t i o n s a n d t r a n s p o r t a t i o n etc. A ll t h e s e r e a s o n s m a k e t h e i m p o r t s h a r e s g r o w v e r y q u ic k ly .
T h e s e t e n d e n c i e s w e r e a n a l y z e d c a r e f u lly . R e c e n tly , t h e s c i e n t i f i c o u t p u t has b e e n c o n c e n t r a t e d o n e s t i m a t i n g o r p r e d i c t i n g th e e f f e c ts o f a c c e s s i o n . A p a r t f ro m p u r e l y q u a l i t a t i v e e l a b o r a t i o n s , m o s t p a p e r s d i s c u s s t h e o r e t i c a l m o d e l s w i t h t h e s u p p o r t o f sta tistic a l e v i d e n c e (e.g. W y s o k i ń s k a a n d W i t k o w s k a 2 0 0 4 , C z a r n y a n d L a n g 2 0 0 2 , C i e ś l i k 2 0 0 1 , M i s a l a 1999). C a l c u l a t i o n s b a s e d o n e m p ir ic a l d a t a u s u a l l y v e r i f y t h e o r i e s o f in te r n a tio n a l t r a d e b y m e a n s o f e s t i m a t i n g s h if ts in f a c t o r c o n t e n t s o f tr a d e , o r c a l c u l a t i n g in t r a - i n d u s t r y t r a d e in d ic e s . L o o k i n g at t h e g r a p h s s h o w i n g t h e i m p o r t s h a r e in total o u t p u t (F ig . 1 1 1 ) w e c a n s e e a g e n e r a l rule: c o m p a r i n g w ith t h e ‘80s, t h e s e s h a r e s m e a s u r e d b o th in c o n s t a n t a n d c u r r e n t p r ic e s h a v e r is e n d r a m a tic a ll y . F o r all c o m m o d i t i e s , th e im p o r t s h a r e r e a c h e d 0 . 2 8 in 2001 sta rt in g f ro m le ss th a n 0.1 in 1990. A ft e r e l e v e n y e a r s , t r a n s i t i o n p r o c e s s s e e m s to b e o v e r for a g r i c u l t u r a l p r o d u c t s , o t h e r n o n m e t a l l i c p r o d u c t s , a n d o t h e r c o m m o d i t i e s . I m p o r t s h a r e s f o r o t h e r c a te g o r i e s a r e still g r o w i n g . It is h a r d to d e c o m p o s e t h is g r o w t h a c c o r d i n g to t h e r e a s o n s m e n t i o n e d a b o v e , b u t a l t o g e t h e r t h e s e t e n d e n c i e s s h a p e th e i m p o r t s h a r e s t i m e s e r ie s in to lo g is tic t i m e t r e n d fu n c tio n s:
a
-cl
y = d + —
—
(1) 1-t-be
w h e r e th e initial v a l u e ,d
+(a -
t/)/( 1 +b)
is th e s h a r e o f i m p o r t s ty p ic a l fo r th e o ld s ty l e e c o n o m y a n d t h e s a t u r a t i o n levela
is t h e s h a r e ty p i c a l f o r a fre e m a r k e t e c o n o m y . A s it c a n b e s e e n , d u m m y v a r i a b l e s w e r e in t r o d u c e d in s o m e c a s e s , e s p e c i a ll y fo r 1 9 9 0 a n d 1 9 9 1 , w h e n t h e m a r k e t c h a n g e d its r u le s a n d s o m e t i m e s w e w i t n e s s e d p r i c e re v o lu t io n s . I n t r o d u c t i o n o f s u c h v a r i a b l e s c h a n g e s th e s h a p e o f t h e t r e n d f u n c t i o n a n d s o m e t i m e s w e h a v e a l te r n a t iv e s lik e o n F i g u r e 9, b u t th e c o n c e p t o f l o g is tic f u n c t i o n s e e m s to b e rig h t. T h e s a m e a p p l i e s to t h e s h a re s m e a s u r e d in c u r r e n t p r ic e s . T h e r e is o n e e x c e p t i o n - p r o d u c t s o f m i n i n g q u a r r y ing, f u e ls a n d e n e r g y , w h e r e w e c a n s e e th a t th e s h a r e in c u r r e n t p r ic e s , a f te r s o m e p e r t u r b a t i o n s , c a m e b a c k to t h e le vel o f 1985. In t h e r ig h t c o l u m n o fg r a p h s t h e r e a r e r a ti o s o f im p o r t p r ic e s to d o m e s t i c p r i c c s ( i n d e x , w h i c h v a l u e in 2 0 0 0 is 1). T h e r e is n o c o m m o n t e n d e n c y here . In f iv e c a s e s ( w h i c h is e x a c t l y a h a l f) w e m a y s a y th a t t h e p r i c e ratio s a f t e r lo n g a n d d r a m a t i c j o u r n e y c a m e b a c k m o r e o r le ss to t h e i r initial le vels. F o r m i n i n g a n d o t h e r n o n - m e t a l l i c p r o d u c t s t h e s e r a ti o s w e n t d o w n , a n d for m e ta l s , m a c h i n e r y a n d t e x tile s t h e y w e n t up. T h e s e th r e e c a s e s s h o w , that th e re exist r e a s o n s for o p e n i n g t h e e c o n o m y w h ic h a r e so stro n g , that e v e n u n f a v o r a b l e c h a n g e s in p r ic e s d o n ’t c o m p e n s a t e th e m .
L o o k i n g at th e g r a p h s w e c a n s e e d if fe r e n t s p e e d o f tr a n s i t i o n p r o c e s s e s . In s o m e c a s e s t h e t r a n s i t i o n s e e m to b e o v e r ( a g r ic u l tu r e , o t h e r n o n m e t a l l i c m ineral p ro d u cts) in s o m e o th e r c a s e s it looks like it w o u ld c o n t in u e for s o m e y e a rs (food p roducts). G e n e r a lly w e c a n say, that the m a in w a v e o f c h a n g e s is b e h i n d us.
Fig. 1 -1 1. Share o f import in total output
From left to right: I) constant prices o f 2000; 2) price ratio, 2000 = I ; 3) current prices (below). I . ЛИ commodities
2. Products o f agriculture, hunting, forestry and fishing
5. Machinery and equipm ent incl. electrical, optical and transport equipm ent
I'rcdicicd g . Actual
ľfťdiťiťtl g . Ai'iuul
8. Wood, w ood products, pulp, paper, paper products, recorded media, printing services
- f . ш ч р й -0 - p ro .l u ll'll I , p r o d ic l rd ?
11. Other commodities I I I . T H E E Q U A T I O N S T i m e t r e n d e q u a t i o n s m i g h t b e u s e d fo r s i m p l e p r o j e c t i o n s b u t a r e not e n o u g h fo r m a k i n g s im u la t io n s . T h e p r o p o s e d e q u a t i o n s h a v e a lo g it form , w h ic h is o f te n u s e d in I N F O R U M m o d e l s ( B a r n a b a n i 1993, W u a n d P an 1998). It is q u i t e s i m i l a r to (1), it just a s s u m e s th a t th e l o w e r a n d u p p e r a s y m p t o t e s a r e 0 a n d 1. T h i s a s s u m p t i o n is n e c e s s a ry , as th e e x p l a i n e d v a r i a b l e is a sh a re . T h e lo git fo rm c a n b e e s t i m a t e d w ith O L S a f te r t r a n s f o r m a t i o n to: ln(/77.v/(l -
mx))
=a () + a, EVt
+a 2EV2 +...
(2) Aw h e r e :
mx - m /(x
-fm)
is t h e s h a re o f im p o r t in total o u t p u t ,m ~
im p o r t in c o n s t a n t p ric e sx
- o u t p u t in c o n s t a n t p r i c e sEV -
e x p l a n a t o r y v a r ia b le s .T h e first e x p l a n a t o r y v a r i a b l e is the p r ic e r e la tio n b e t w e e n i m p o r t a n d d o m e s tic g o o d s . T h e i m p o r t p r ic e s w e r e c o r r e c t e d w ith d u t i e s a n d o t h e r t a x e s r e la ted to im p o r ts , so th e v a r i a b l e s a r e n o t e x a c t ly t h e s a m e a s c a n b e s e e n in F i g u r e s 1-11 o n th e right. T h e s e v a r i a b l e s a r e p r e s e n t in all e q u a t i o n s , b e c a u s e th e p r ic e ratio , c h a n g e s in d u t i e s a n d e x c h a n g e r a te a re th e m o s t o f te n u s e d i n s t r u m e n t s for s i m u l a t i o n s . A s th e r e w a s n o i n f o r m a t i o n a b o u t d u t i e s in th e e ig h tie s , e s t i m a t i o n s w e r e b a s e d o n th e p e r io d 1 9 9 0 - 2 0 0 1 . C h a n g e s in p r ic e s , d u t i e s a n d e x c h a n g e r a te s a r e n o t e n o u g h to e x p l a i n so d r a m a t i c a l rise in th e s h a r e s . T h a t is w h y all e q u a t i o n s a r e s u p p o r t e d w ith a n o t h e r v a r ia b le . In th e p r e v i o u s v e r s io n , th e ro le o f th e s e c o n d e x p l a n a t o r y v a r i a b l e w a s p l a y e d b y a m e a s u r e o f f o re ig n d ir e c t i n v e s t m e n t . It w a s a s s u m e d tha t th e r e w e r e tw o e f f e c ts o f th e F D I here: o n e w a s i m m e d i a t e a n d p o s i t i v e - fo r eig n c o m p a n i e s i m p o r t m a c h i n e s a n d s u p p li e s . In l o n g e r t e r m , w i t h s o m e t i m e lags, th e FDI m a k e th e d o m e s t i c p r o d u c t i o n m o r e c o m p e t i t i v e , p u s h i n g o u t im ports. U s i n g th e n e w d a t a set it w a s n o t p o s s i b l e to s e p a r a t e t h e s e t w o e f f e c ts , o r th e y a p p e a r e d in s i g n if i c a n t, n e v e r t h e l e s s , th e n e w e s t i m a t e s s h o w e d th a t th e FDI w a s r a t h e r n o t a g o o d c h o ic e . S o, t h e r e a r e t h r e e ty p e s o f „ a n o t h e r v a r i a b l e ” p r o p o s e d : T o ta l o u t p u t :
(x + m)
C h a n g e s in to tal o u t p u t in th e f o rm o f c h a in in dex:(x, + m l ) / ( x l_]
+ / « , _ , ) T i m e tr e n d : l n ( / ) o r / / ( , 0 < / ? < 1T h e r e a r e tw o r e a s o n s fo r i n tr o d u c tio n o f to tal o u t p u t o r c h a n g e s in total o u t p u t as a n e x p l a n a t o r y va ria b le :
1) in s h o r t t e r m im p o r t is m o r e fle x ib le f o r c h a n g e s in d e m a n d th a n d o m e s tic p r o d u c t i o n . D o m e s t i c p r o d u c e r s a r e o f te n n o t a b l e to q u i c k l y r e f le c t a n in c r e a s e in d e m a n d . In th e n i n e tie s ( e s p e c ia lly th e first h alf) t h e r e w a s a p r o b l e m o f t h e s t r u c t u r e o f p o te n tia l p r o d u c t i o n , w h ic h d i d n ’t m a t c h w e ll to th e d e m a n d . In o t h e r w o r d s , p r o d u c e r s w e r e a b l e to p r o d u c e e n o u g h g o o d s , b u t n o t e x a c t ly o f th e k in d w h i c h w o u l d h a v e b e e n b o u g h t b y p e o p le . T h i s p r o b l e m h a s m o r e lo n g t e rm c h a r a c t e r in th e c a s e o f m i n i n g p r o d u c t s a n d fuels. In th is e q u a t i o n ( a n d o n ly in th is e q u a t i o n ) total o u t p u t w a s u se d in ste a d o f its c h a i n in d e x .
2) in lo n g t e r m it m a y r e f le c t th e e f f e c t o f s c a l e a n d in tra in d u s t r y tra d e , b u t th is is r a t h e r w e a k h y p o th e s is .
I V. R E S U L T S O F E S T I M A T I O N O F I M P O R T S H A R E E Q U A T I O N S
E s tim a tio n s w e r e m a d e u sin g G 7 so f tw a r e (see w w w . l n f o r u m W e b . u m d . e d u ). T h e re s u lts a r e s h o w n b e l o w in th e f o rm o f th e o r ig in a l p r i n t o u t s . All s y m b o l s u s e d at th e p r i n t o u t s a r e e x p l a i n e d b e l o w ( s e e th e G 7 M a n u a l) : S t a n d a r d e r r o r o f e s tim a te . C o e f f i c i e n t o f m u l t i p l e d e t e r m in a tio n . A u t o c o r r e l a t i o n c o e f f ic ie n t o f the re sid u a ls. N u m b e r o f o b s e r v a tio n s . T h e S E E for f o r e c a s ts o n e p e r io d a h e a d u s in g rh o a d j u s t m e n t . R S Q a d j u s t e d fo r d e g r e e s o f f re e d o m . D u r b i n - W a t s o n statistic. ( D e g r e e s o f f r e e d o m ) = O b s e r - n u m b e r o f in d e p e n d e n t v a r ia b le s . M e a n a b s o l u t e p e r c e n t a g e error. R e g r e s s i o n c o e f fic ie n t. ( M a r g i n a l e x p l a n a t o r y v a lu e ) T h e p e r c e n t a g e i n c r e a s e in S E E i f th is v a r i a b l e is left o u t o f th e r e g r e s s io n . S tu d e n t t v alu es.
E la s tic ity o f the d e p e n d e n t v a r i a b l e w ith r e s p e c t to th is v a r ia b le , e v a l u a t e d at th e m e a n s o f both. N o r m a l i z e d r e s id u a ls . T h e ratio o f th e s u m o f s q u a r e s r e s id u a ls a f t e r t h e i n t r o d u c t i o n o f this v a r ia b le to th e s u m o f s q u a r e d r e s i d u a l s a f te r all v a r ia b le s h a v e b e e n in tr o d u c e d . W h a t t h e r e g r e s s i o n c o e f f i c i e n t w o u l d b e i f b o t h th e i n d e p e n d e n t a n d d e p e n d e n t v a r i a b l e s w e r e s c a le d so th a t th e y h a d u n i t s t a n d a r d d e v i a ti o n s . T h e F i s h e r F statistic. V a r i a b l e n a m e s a r e a s f o llo w s :
m
- i m p o r tx -
o u t p u tmx
=m /(x
+m)
tmx
= 1п(/ил7(1 -mx))
p d m x
- p r i c e ratio: im p o r t p r i c e d e f la to r ( i n c l u d i n g d u t i e s a n d o t h e r i m p o r t ta x e s) d i v i d e d b y t h e p r i c e d e f l a t o r o f d o m e s t i c p r o d u c t i o n N u m b e r s in s q u a r e b r a c k e ts , f o l l o w i n g th e n a m e o f a v a r i a b l e i n d ic a t e the ti m e lag. N o t e , tha t th e f ig u re s s h o w im p o r t s h a r e s{mx)
n o t th e tr a n s f o r m e d v a r i a b l e stmx.
S q u a r e s lines r e p r e s e n t th e o re tic a l v a l u e s , w h i l e + s i g n s s h o w a c tual sh a re s.SEE
RSQ
RHO
Obser
SEE+I
RBSQ
D W
Do Free
MAPE
Reg-Cocf
Mexval
t-value
Elas
NorRes
Beta
F-stat
A l l c o m m o d i t i e s S E E = 0 . 0 9 S E E + 1 = 0 . 0 9 M A P E = 6 . 0 5 V a r i a b l e n a m e 0 t m x 1 i n t e r c e p t 2 p m d x R S Q R B S Q = 0 . 9 4 4 3 R H O = = 0 . 9 3 2 0 D W = - 0 .0 3 O b s e r = 2 . 0 5 D o F r e e = 12 f r o m 1 9 9 0 . 0 0 0 9 t o 2 0 0 1 . 0 0 0 R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t 1 . 2 4 3 1 5 - 3 . 1 8 6 3 5 2 0 . 1 2 4 0 . 1 - 0 . 8 9 2 . 5 1 1 7 . 9 6 1 . 6 2 1 . 9 9 4 - 0 . 8 6 0 - 9 . 7 5 3 7 6 . 3 3 3 ( x + m ) / ( x [ l ] + m [ l ] ) 0 . 8 4 1 4 4 2 7 . 2 - 0 . 6 2 1 . 0 0 0 . 2 0 8 2 . 3 5 7 5 . 5 5 1. P r o d u c t s o f a g r i c u l t u r e , h u n t i n g , f o r e s t r y a n d f i s h i n g S E E = 0 . 1 4 S E E + 1 = 0 . 1 4 M A P E = 4 . 7 6 V a r i a b l e n a m e 0 t m x l 1 i n t e r c e p t 2 p m d x l 3 @ l o g ( t ) R S Q R B S Q = 0 . 9 3 8 6 R H O = = 0 . 9 2 4 9 D W = 0 . 0 5 O b s e r 1 . 8 9 D o F r e e 12 f r o m 1 9 9 0 . 0 0 0 9 t o 2 0 0 1 . 0 0 0 R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t - 2 . 5 6 7 7 3 - 1 . 1 0 0 0 3 0 . 5 7 5 0 2 All com m odities
2 5 3 . 5 0 . 9 7 1 6 . 2 8 - 1 0 . 1 7 3 1 0 6 . 0 0 . 3 9 8 . 8 7 - 0 . 4 6 6 - 5 . 4 0 4 6 8 . 7 5 1 9 7 . 9 - 0 . 3 6 1 . 0 0 0 . 7 2 6 8 . 4 1 7 7 0 . 8 5 P roducts o f agriculture... 2. P r o d u c t s o f m i n i n g , q u a r r y i n g , f u e l s a n d e n e r g y S E E = 0 . 0 9 R S Q = 0 . 7 4 5 5 R H O = 0 . 1 6 O b s e r = S E E + 1 = 0 . 0 9 R B S Q = 0 . 6 8 9 0 D W = 1 . 6 8 D o F r e e = M A P E = 4 . 9 6 V a r i a b l e n a m e 0 t m x 2 1 i n t e r c e p t 2 p m d x 2 3 (x2 + m2 ) 12 f r o m 1 9 9 0 . 0 0 0 9 t o 2 0 0 1 . 0 0 0 R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t - 4 . 0 4 6 1 5 - 0 . 5 4 7 6 7 0 . 0 0 0 0 2 1 4 9 . 2 5 4 . 1 8 5 . 4 2 . 5 1 0 . 2 9 - 1 . 8 0 3 . 9 3 3 . 4 4 1.00 - 6 . 8 4 7 - 3 . 5 1 6 4 . 6 8 5 1 3 . 1 8 2 1 . 9 5
3. B a s i c m e t a l s a n d f a b r i c a t e d m e t a l p r o d u c t s S E E = 0 . 0 5 S E E + 1 = 0 . 0 5 M A P E = 3 . 5 9 V a r i a b l e n a m e 0 t m x 3 1 i n t e r c e p t 2 p m d x 3 3 @ p o w ( t , .63) R S Q R B S Q = 0 . 9 8 1 7 R H O = = 0 . 9 7 7 6 D W = 0 . 0 4 O b s e r = 1 . 9 2 D o F r e e = 12 9 f r o m 1 9 9 0 . 0 0 0 t o 2 0 0 1 . 0 0 0 R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t - 2 . 2 3 2 7 3 - 0 . 2 5 9 5 4 0 . 3 5 7 9 8 7 2 9 . 0 1 3 . 4 4 4 5 . 3 1 . 7 0 0 . 1 5 -0.85 5 4 . 5 9 2 9 . 7 4 - 0 . 1 0 6 1 . 0 0 1 . 0 6 6 - 2 4 . 6 8 8 - 1 . 6 0 6 2 4 1 . 1 4 1 6 . 0 8 2 2 5 8 . 6 4
Products o f m ining... Basic m etals.
4. M a c h i n e r y a n d e q u i p m e n t i n c l . e l e c t r i c a l , o p t i c a l . . . S E E = 0 . 0 7 R S Q = 0 . 9 5 2 8 R H O = S E E + 1 = 0 . 0 7 R B S Q = 0 . 9 4 2 3 D W = M A P E = 1 4 . 3 2 0 . 3 6 O b s e r = 1 . 2 9 D o F r e e = 12 f r o m 1 9 9 0 . 0 0 0 9 t o 2 0 0 1 . 0 0 0 V a r i a b l e n a m e 0 t m x 4 1 i n t e r c e p t 2 p m d x 4 3 @ l o g ( t ) R e g - C o e f M e x v a l E l a s N o r R e s B e t t - v a l u e F - S t a t - 0 . 5 6 3 0 7 5 6 . 8 1 . 1 2 2 1 . 2 0 - 3 . 6 2 3 - 0 . 6 2 5 2 5 7 0 . 5 1 . 3 1 2 1 . 1 6 - 0 . 3 1 1 - 4 . 1 4 1 9 0 . 8 8 0 . 4 3 2 3 8 3 6 0 . 0 - 1 . 4 3 1 . 0 0 1 . 0 1 2 1 3 . 4 7 0 1 8 1 . 4 5 5. C h e m i c a l , r u b b e r a n d p l a s t i c p r o d u c t s S E E = 0 . 1 6 R S Q S E E + 1 = 0 . 1 6 R B S Q M A P E = 3 0 . 0 6 V a r i a b l e n a m e 0 t m x 5 1 i n t e r c e p t 2 p m d x 5 0 . 8 2 7 4 R H O = 0 . 7 8 9 0 D W = 0 . 3 5 O b s e r 1 . 2 9 D o F r e e 12 f r o m 1 9 9 0 . 0 0 0 9 t o 2 0 0 1 . 0 0 0 R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t -1. 5 7 7 8 8 - 1 . 4 2 9 0 0 4 2 . 9 9 2 . 3 2 . 3 4 2 . 52 5 . 7 9 4 . 3 1 - 0 . 7 0 6 - 3 . 0 6 2 - 4 . 9 2 7 2 1 . 5 7 3 ( x 5 + m 5 ) / ( x 5 [ 1 ] + m 5 [ 1 ] ) 2 . 3 9 4 3 3 1 0 7 . 5 - 3 . 8 6 1 . 0 0 0 . 7 8 1 5 . 4 5 5 2 9 . 7 5
M achinery and equipm ent... C hem ical, rubber... S E E = 0 . 2 0 S E E + 1 = 0 . 2 0 M A P E = 8 . 6 3 V a r i a b l e n a m e 0 t m x 6 1 i n t e r c e p t 2 p m d x 6 6. O t h e r n o n - m e t a l l i c m i n e r a l p r o d u c t s R S Q R B S Q 0 . 8 4 1 8 R H O = 0 . 8 0 6 7 D W = - 0 . 05 O b s e r 2 . 1 0 D o F r e e 12 f r o m 1 9 9 0 . 0 0 0 9 t o 2 0 0 1 . 0 0 0 R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t - 2 . 9 5 6 5 5 - 1 . 9 6 5 5 0 3 ( x 6 + m 6 ) / ( x 6 [ 1 ] + m 6 [1]) 3 . 0 7 8 6 6 4 0 . 2 1 . 5 6 6 . 3 2 - 2 . 9 4 7 7 2 . 2 1 . 1 7 3 . 1 8 - 0 . 5 7 2 - 4 . 2 0 7 2 3 . 9 5 7 8 . 5 - 1 . 7 3 1 . 0 0 0 . 6 0 3 4 . 4 3 4 1 9 . 6 6 W o o d , w o o d p r o d u c t s , p u l p , p a p e r , p a p e r p r o d u c t s , . . . = 0 . 8 8 1 5 R H O = = 0 . 8 5 5 2 D W = 0 . 4 9 O b s e r = 1 . 0 2 D o F r e e = 12 f r o m 1 9 9 0 . 0 0 0 9 t o 2 0 0 1 . 0 0 0 S E E = 0 . 1 5 R S Q S E E + 1 = 0 . 1 3 R B S Q M A P E = 7 . 5 7 V a r i a b l e n a m e R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t 0 t m x 7 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1 i n t e r c e p t - 0 . 3 4 7 4 8 1 .2 0 . 1 8 8 . 4 4 - 0 . 4 6 6 2 p m d x 7 - 3 . 4 6 8 3 0 1 2 7 . 4 2 . 0 5 4 . 5 6 - 0 . 7 0 4 - 6 . 1 2 7 3 3 . 4 7 3 ( x 7 + m 7 ) / < x 7 [ 1 ] + m 7 [1]) 2 . 1 3 5 9 7 1 1 3 . 5 - 1 . 2 3 1 . 0 0 0 . 6 5 0 5 . 6 5 9 3 2 . 0 2
O ther non-m etallic... W ood, w ood products.. : 8 . S E E = 0 . 0 7 S E E + 1 = 0 . 0 6 M A P E = 8 . 6 5 V a r i a b l e n a m e 0 t m x 8 1 i n t e r c e p t 2 p m d x 8 3 @ l o g ( t ) T e x t i l e s , t e x t i l e p r o d u c t s a n d w e a r i n g a p p a r e l , . . R S Q = 0 . 9 4 8 8 R H O = R B S Q = 0 . 9 3 7 4 D W = - 0 .3 8 O b s e r = 2 . 7 5 D o F r e e = 12 9 f r o m 1 9 9 0 . 0 0 0 t o 2 0 0 1 . 0 0 0 R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t - 1 . 1 3 6 5 3 2 0 5 . 5 1 . 6 3 1 9 . 5 4 - 8 . 6 6 1 - 0 . 4 2 2 0 5 2 1 . 9 0 . 5 4 1 1 . 7 7 - 0 . 2 4 3 - 2 . 0 9 1 8 3 . 4 2 0 . 4 8 9 4 0 2 4 3 . 1 - 1 . 1 7 1 . 0 0 1 . 1 4 7 9 . 8 4 7 9 6 . 9 7 F o o d p r o d u c t s , b e v e r a g e s a n d t o b a c c o S E E = 0 . 0 8 R S Q S E E + 1 = 0 . 0 8 R B S Q M A P E = 2 . 7 0 V a r i a b l e n a m e 0 t m x 9 1 i n t e r c e p t 2 p m d x 9 3 < x 9 + m 9 ) / ( x 9 [ 1 ] + m 9 [ 0 . 8 0 2 5 R H O = 0 . 7 5 8 7 D W = 0 . 1 8 O b s e r = 1 . 6 3 D o F r e e = 12 9 f r o m 1 9 9 0 . 0 0 0 t o 2 0 0 1 . 0 0 0 R e g - C o e f M e x v a l E l a s N o r R e s B e t a t - v a l u e F - S t a t - 2 . 6 1 0 9 2 - 0 . 7 9 1 5 9 I 1 0 . 9 9 1 0 3 1 2 9 . 3 5 4 . 3 1 . 0 6 0 . 3 6 5 9 . 3 - 0 . 4 2 5 . 0 6 2 . 5 4 1 . 0 0 - 0 . 5 4 4 0 . 57 4 - 6 . 1 9 1 - 3 . 5 2 6 3 . 7 2 0 1 8 . 2 9 1 3 . 8 4
T extiles... Food products...
In m a n y c a s e s r e l a t i v e p r i c e s a n d c h a n g e s in to tal o u t p u t a p p e a r e d to e x p l a in q u i t e a lot o f th e p r o c e s s d e s c r i b e d o n Fig. 1-11 b y th e t r a n s i t i o n c u r v e s . In o t h e r c a s e s , w h e r e total o u t p u t w a s n o t s ig n i f ic a n t ( o r h a s lo w M e x v a l ) , th e t i m e tr e n d w a s p u t in th e lo g f o rm , o r a s a root. T h u s , th e r e a s o n s for t r a n s i tio n p r o c e s s w e r e d e c o m p o s e d in to tw o : c h a n g e s in p ric e s a n d o t h e r r e a s o n s . T h e lo g tr e n d , w h i c h is s i m i l a r to a r o o t w h e r e b e t a is c l o s e to z e ro , m e a n s th a t th e n o n - p r i c e fa c to rs ra is e d th e s h a r e s tr o n g l y in th e b e g i n n i n g o f th e a n a l y z e d p e r i o d ( 1 9 9 0 -2 0 0 1 ) , w e a k e n i n g v e r y q u ic k ly . T h i s c o u l d b e o b s e r v e d fo r a g r i c u l t u r a l p r o d u c t s , m a c h i n e r y a n d te x tile s , a n d m e a n s , th a t t h e s e b r a n c h e s h a v e c o m p l e t e d th e t r a n sitio n p e r io d . H i g h e r v a l u e o f b eta, like 0 .6 3 e s t i m a t e d 1 fo r m e ta l s , s u g g e s t s , tha t th e t r a n s i tio n p r o c e s s in th is in d u s t r y is g o i n g to c o n t i n u e ( s e e a l s o Fig. 4).
F o r th e c a t e g o r y " o t h e r c o m m o d i t i e s ” n o r e a s o n a b l e e q u a t i o n c o u l d b e p r o p o s e d .
T h e m a in g o a l o f th e c a lc u l a t i o n s s h o w e d a b o v e w a s to m a k e th e im p o r t e q u a t i o n s o p e r a t i o n a l . T h e first, s y m p t o m a t i c v e r s io n o f t h e e q u a t i o n s w ill s e r v e as th e b a s e for l o n g t e r m p r o j e c t i o n s , the s e c o n d w ill b e u s e d to s i m u l a t e th e r e ac tio n o f i m p o r t s o n c h a n g e s in d u tie s, a s w ell a s in d o m e s t i c p r ic e s . T o d o this, th e s e e q u a t i o n s w ill b e i n c lu d e d into I M P E C w ith a b r i d g e m a t r i x c o n v e r t i n g r e s u lts o b t a i n e d fro m 10 e q u a t i o n s in to 57 b r a n c h e s . C o n s t r u c t i o n o f th is b r i d g e will p r o b a b l y b r i n g o t h e r i n te r e s ti n g fin d in g s.
1 Equations with time trend were first estimated using G7 with nl (nonlinear estimation) command. If beta appeared to be under 0.01, the root was replaced with log. Then the equations were estimated using r com m and (OLS) with beta given explicitly.
R E F E R E N C E S
B a r n a b a n i M. (1 9 9 3 ), Logit Model Applied in Import Market Shares: Tlie Italian Case, 1st W o rld IN F O R U M C o n fe re n c e , R en n es
C i e ś l i k A . (2 0 0 1 ), Przewaga komparatywna a struktura handlu zagranicznego Polski, W ia d o m o śc i S ta ty sty c z n e , vol. 6, pp. 1 9 -2 9
C z a r n y E ., L a n g G . (2 0 0 2 ), Poland 's Accession to EU. Some Lessons fro m the In ternational Trade Theory, B ank i K red y t 2, pp. 2 0 -3 0
M i s a I a .1 .(1 9 9 9 ), Czynniki wytwórcze w wymianie zagranicznej Polski, “G o sp o d a rk a N a ro d o w a ” , v o l. 10, pp. 3 8 - 5 4
P r z y b y l i ń s k i M. ( 19 9 8 ), Including FDI into Foreign Trade Equations. The Case o f Poland, VI IN F O R U M W o rld C o n fe re n c e , El E scorial, M ad rid , S e p te m b e r 1998 W u H ., P a n S. (1 9 9 8 ), Import-Export Equations fo r Miulan Model, VI W orld IN FO -
R U M C o n fe re n c e , El E sco rial, M ad rid
W y s o k i ń s k a Z. , W i t k o w s k a J. (2 0 0 4 ), Integracja europejska. Dostosowania w Polsce w dziedzinie polityk, P o lsk ie W y d aw n ictw o E k o n o m ic z n e , W arszaw a
Michał Przybyliński
R Ó W N A N IA U D ZIA ŁU IM PO RT U W PO PY CIE G L O B A L N Y M DLA M O D E L U IM PEC
B lok im p o rtu w ty p o w y m m o d e lu IN F O R U M z a w ie ra ró w n a n ia o p is u ją c e u d ział im p o rtu w p o p y c ie c a łk o w ity m . P o d o b n e ro z w ią z a n ie p rz y ję to d la p o ls k ie g o m o d elu IM P E C . W o p ra c o w a n iu p rz e d s ta w io n o w y n ik i o s z a c o w a ń ta k ic h w ła śn ie ró w n ań zb u d o w a n y c h w d w ó c h w a ria n ta c h . P ierw szy z nich p o le g a ł na z a s to so w a n iu tren d u lo g isty c z n e g o i o sz a c o w a n iu k rz y w y c h , u k azu ją c y c h tra n sfo rm a c ję (w z ro st o tw a rto śc i) p o lsk iej g o s p o d a rk i w latach 1 9 8 5-2001. W a ria n t ten, p o k a z u ją c y te m p o p rz e m ia n c h a ra k te ry sty c z n e d la p o s z c z e g ó ln y c h a n a liz o w a n y c h g ru p to w a ró w , m o ż e by ć w p ro sty sp o só b w y k o rz y s ta n y do p ro je k c ji u d z ia łó w im p o rtu w p o p y c ie c a łk o w ity m , co p o k a z a n o .
D rugi w a ria n t, to ró w n a n ia p rz y c z y n o w o -sk u tk o w e , u z a le ż n ia ją c e b a d a n e u d z ia ły od relacji cen im p o rtu do cen k ra jo w y c h . D ru g ą z m ie n n ą o b ja ś n ia ją c ą w ró w n a n ia c h je s t p o zio m lub p rz y ro s t p o p y tu , a w n ie k tó ry c h p rz y p a d k a c h z m ie n n a c z a s o w a o sp e c ja ln ie d o b ran ej p o sta c i. T a k ie ró w n a n ia p o z w a la ją na sy m u la c ję z m ia n re la c ji c e n o w y c h (łą c z n ie ze z m ia n a m i k u rsu w a lu to w e g o ) i s ta n o w ią a lte rn a ty w ę d la ró w n a ń tren d u w p rz y p a d k u b a rd z ie j z ło ż o n y c h a n a liz sy m u lacy jn y ch .
