I Heiko Hesse (2008) sir dung so lieu gOp dm 99 qu'Oc gia; Anwesha Aditya va Saikat Sinha Roy (2010) sir dung so lieu ctia 65 quOc gia; Arailym Kadyrova (2011) sir dung so lieu cila 88 quoc gia
8He so tuang quan hang Spearman (SRC) la met kiem dinh, phi tham so, thuang dugc sir dung de kiem dinh tinh dec lap cua hai bier) ngau nhien x va y Ban chat cua mei lien he gii-Tra cac bin & day la
kiem dinh tinh dec lap cua hai bier) ngau nhien x va y. Ban chat cua mei lien he gii-Tra cac bin & day la lien he gifra cac hang chir khong phai lien he giira cac gia tri. Neu he so SRC cang gan +1 hoac -1, chirng to c6 mei tuang quan thir hang chat che, va nguvc lai he so SRC cang gan0 co nghia la it co sty tuang quan. Khi,he so trong quan hang co xu huemg giam dan qua thoi gian, diet' do ham y rang thu hang dm cac bien thay doi, hay not each khac cau true gi6 hang hoa xuat khau cua Viet Nam co six thay doi.
Bang 2.5: He so tircrng quan h#ng Spearman difii v(fri chi so PRODY va RCA
Nam PRODY*PRODY RCA*RCA
2001 1,000 1,000 2002 0,797(**) 0,841(**) 2003 0,749(**) 0,760(**) 2004 0,734(**) 0,749(**) 2005 0,686(**) 0,715(**) 2006 0,676(**) 0,683(**) 2007 0,692(**) 0,651(**) 2008 0,668(**) 0,630(**) 2009 0,653(**) 0,628(**) 2010 0,623(**) 0,609(**) 2011 0,574(**) 0,565(**)
** Correlation is significant at the 0,01 level (2-tailed).
Nguan: Tinh tam cfia tric gia tic so lieu thong k'e cfia WB va UN Comtrade
Phan tich chi tiet mirc d6 phirc tap dia tdng mat hang hoac mot nhom hang xuat
khdu dugc the hien thong qua chi s6 PRODY. Tu bieu 6 2.10 cho thay mirc d6 phirc
tap cilia cac mat hang xuat khau Viet Nam co xu huang ra tang qua cac nam (trung binh hang nam tang 10,3%). Trong do sr gia tang mirc d6 phirc tap cua nh6m hang the bien giai doan 2001-2011 tang trung binh 11,4%, dm nhOm hang filo, mai so the tang trung binh 8,3%. Cao han so vai tOc d6 tang thu nhdp binh quan dau ngtrai cilia Ca nuac. Dieu nay phan anh, cac mat hang xuat khAu, co t6c d6 tang nang suat cao hon so Wei binh quan chung cua ca ntrac. Dang luu y, nhfing mat hang c6 chi s6 PRODY cao cilia Viet Nam van chit yeti la cac san phAm trong cum hang the bien phan lo4i theo nguyen lieu, hoa chat, luong thuc, thuc pham, (ILI ma, chat beo...Day la nhung mat hang tho, so the hoac nhung mat hang the bien Oa tr'en tai nguyen.
Nhu v4y, co the thay cau truc gio hang h6a xuat khdu cua Viet Nam trong thai gian qua chuyen dich theo huang nang cao ham ltrang cong nghe, MuC d6 the bien va mirc d6 phirc tap dm san phAm. Hay not cach khac co cau mat hang xuat khau cua Viet Nam có xu huang da dang hOa theo chi'eu sau. Tuy nhien, xu huang nay din ra chi yeti a nhung mat hang Oa vao khai thac lqi the san co ve tai nguyen thien nhien, cac nganh the tao cong nghe thap sir Ong nhieu lao d6ng va san xuat cac cau kien,
Luang thu•c. thu•c pham va dOng vat
song 5000
4000
NvL tho, khong diing 6 an, tru•
nhien lieu
Nhieu lieu, dau ma nhan va vat lieu
lien quan Hang h6a the tac
hqn hop
May mac, phkrang tin van tai va phy
tung
Hang che" Wen phan loaitheo nguyen lieu DO u6ng va thu6c la Nam 2001 —a-- Nam 2006 Nam 2011
Hoa chat va san pham lien quan
Dau, ma, chat Pao, sap Ong, thkrc vat
ding nghe trung binh. Da dang h6a theo chieu sau nhung phv thuOc nhieu vao nguyen ph4 lieu, may mOc thiet bt va ding nghe nuac ngoai, tST le not dia 116a thdp. Vai phuang thirc da clang hoa nhu vay, khong chi gay can kiet ngu6n tai nguyen thien nhien, han the kha nang nang cao chu8i gia tri san phdm xuat khdu, ma con anh Inramg xdu den six phat trien ben yang dia nen kinh
Bien do 2.10: Chi so PRODY cac nhOm hang xuat khan clia Viet Nam
Ngujn: Tinh toan cita tac gia tir se; lieu thong ice ctia WB va UN Comtrade
2.2.4. Phan tich da clang hoa dtra tren chi so Theil Etropy
De phan tich sau sir da dang hoa giira cac nham hang va su da clang hoa trong ding mot nharn hang xuat khau, luan an sir dung chi so Theil Etropy (TheilT). Chi s6 Theil Etropy cang ton, thi mirc di) da clang hoa mat hang xuat khdu cang cao. Bieu do 2.12 cho thy chi s6 TheilT (do luerng da dang hoa chung) cua Viet Nam co xu huong gia tang. Nam 2001 chi so TheilT cac mat hang xuat khdu cila Viet Nam la 2,98, den
nam 2007 tang len 3,1 va nam 2011 la 3,23. Dieu nay phan anh cac mat hang xuat khau cilia Viet Nam ngay cang duac da clang h6a. Neu so vai cac nuac tren the giai, Viet Nam thuOc nh6m nu& co mirc dO da clang h6a trung binh thdp cua th'e
9 Theo tInh toan cila Olivier Cadot, Celine Carrere, Vanessa Strauss-Kahn (2009), chi so TheilT cua 156 quOc gia tren the gied giai doan 1988-2006 la 4,8 vai sai so 1,79 156 quOc gia tren the gied giai doan 1988-2006 la 4,8 vai sai so 1,79
Chi s6 da dung hcia ma't hang xugt khgu Theil Etropy 3.3 3.2 3.1 - 3 2.9 -- 2.8 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 (adsbygoogle = window.adsbygoogle || []).push({});
Bien di 2.11: Chi s'4 da ding hoa mat hang xuat khan Theil Etropy
Ngtain: Tinh Wan cfia tac gia dtra tren sa lieu thong ke cfia UN Comtrade
Di sau phan ra chi s6 TheilT thanh hai phan la da ding hoa glib cac nhOm hang (Theilb) va da clang h6a trong not 1)0 nhom hang (Theilw). Ket qua tinh toan cho thay, chi s6 Theilb va Theilw au co xu huong tang. Chi s6 da ding hoa Oita cac nhom hang (Theilb) tang to 1,889 nam 2001 len 2,029 nam 2011, tire la tang 0,14 don vi. Chi so da ding trong not bO nhom hang tang tir 1,096 nam 2001 len 1,205, tirc la tang 0,108 don vi. Nhu vay, mac du au c6 xu huong tang, nhung mire do gia tang da ding hoa gifra cac nhom hang cao hon mix dO gia tang da ding hoa trong not bO nhom hang.
Bang 2.6: Da clang Wm gifra cac nh6m hang va da clang 116a trong not bo nhom hang
2001 2003 2005 2007 2009 2011
Theilb 1.889 1.897 1.933 2.008 2.108 2.029
Theilw 1.096 1.104 1.014 1.100 1.172 1.205
TheilT 2.986 3.001 2.947 3.108 3.280 3.235
Tinh toan cua tac gia chra tren s a lieu thong ke cfia UN Comtrade
Hon nira, chi s6 Theilb co gia tri cao gin gap doi so vii chi s6 Theilw, diL nay cho thy su da clang hoa gift cac nh6m hang dien ra m4nh hon so vOi da clang hoa trong not 1)0 nhom hang. Hay not each khac la phuong thirc da dang hoa dm Viet Nam chn y'eu la da ding h6a theo chieu rOng, chiem khoang 64%, con da dpg hoa
theo chieu sau chi chiem khoang 36%10. Nhu vay, co the thdy mac du gag mat hang xudt khdu oh Viet Nam c6 xu hung da clang hga, nhung chit yeu la ma Ong sang cac linh vIgrc moi, con phat trien sau cac san phAm trong gang mot nh6m hang cOn han che. Dac diem nay anh huang khong nho den kha nang canh tranh va phat then ben viing cua cac mat hang xudt khAu dia. Viet Nam. Bai vi nhieu nghien ciru dux nghiem tren the giai cho thdy, da clang hga trong not b6 nh6m hang co ham luting che bien va gia tri gia tang cao han so vai da clang h6a gitta gag nhOm hang Wei nhau.
2.2.5. Phan tich da clang hoa lqi th'' so sanh cua cac mat hang xuat khau
Khai niem lgi the so sanh dugc D.Ricado dua ra t& nam 1817, sau nay &rag Herscher, Ohlin va Samuelson tier) tnc phat trien thanh ly thuyet "Lgi the so sanh dva tren so hint cac yeu to ddu vao" nhu lao d6ng, van, tai nguyen, gong nghe...Tuy nhien de danh gia lgi the so sanh cua mgt qu6c gia rat phirc tap. De giai quy& van de nay, nhieu nghien ciru da sir dung chi s6 lgi the so sanh hien him (RCA) do Balassa de xuAt nam 1965. Trong phdn nay luan an sir dung sir dung chi s6 RCA de phan tich sit da dang h6a lgi the so sanh cac mat hang xuAt khAu cua Viet Nam. Sir da clang h6a lgi the
so sanh dugc the hien tren 2 khia canh: (i) sit gia tang s6 luting chiing loai mat hang
c6 RCA cao, hoac ty le so luting chung loai mat hang co RCA cao trong tong so chung loai mat hang dugc xep hang; (ii) He s6 twang quan hang Spearman. Dva tren du lieu thong ke thuong mai qu6c to phan loai theo tieu chuAn ngoai thuong SITC, ket qua tinh toan cho thdy s6 luting chimg 14 mat mat hang xuAt khAu co lgi the so sanh cao (RCA > 1) dia. Viet Nam ngay cang dugc ma Ong. Tir bieu d6 2.12 cho thdy: nam 1991, s6 mat hang xuAt khAu cita Viet Nam co lgi the so sanh la 33 mat hang, den nam 1996 c6 41 mat hang, nam 2001 c6 45 mat hang, nam 2006 co 48 mat hang, va nam 2011 tang len 52 mat hang. Nhu vay, sau 20 nam Viet Nam da c6 them 19 mat hang c6 lgi the so sanh, tic la trung binh moi nam chimg to c6 them mot chting loai mat hang c6 lgi the so sanh. Dieu nay rat coy nghia, nhAt la trong b6i canh to do hga thtrong mai va canh tranh toan cdu gay gat nhu hien nay.
De do luting sit thay d6i lgi the so sanh cua gi6 mat hang xuAt khdu, luan an sir citing he s6 tuang quan hang Spearman d6i vai chi s6 RCA. Neu he s6 tuang quan
hang c6 xu huang giam clan qua tiled gian, dieu dO ham y rang c6 sly da clang h6a lgi
the so sanh trong cdu tritc gig hang hoa xuAt khAu dm Viet Nam. Ket qua tinh toan Bang 2.5 cho thdy he so tuang quan hang giam dan to 0,841 nam 2002 xtiong cOn
I° Theo lap luan dm Olivier Cadot, Celine Carrere, Vanessa Strauss-Kahn (2009) chi s6 Theilb phan anh stir da clang hoa theo chieu rOng (extensive margin), con Theilw phan anh da clang hoa theo chieu sau (intensive margin)
0,68 nam 2006 va 0,565 nam 2011. Nhu vdy, co sir da clang va thay dOi lgi the so sanh trong cdu true gi6 hang hoa xudt khdu cud. Viet Nam.