22 I Vii Bang Tam Si Eric Iksoon Im | 22 - 40
Tac dong ciia thien tai doi voi thu nhap, dau tu- nha a va boat dong noi thirong
6- Viet Nam giai doan 2002-2011
VU BANG T A M Tnrong Dai hoc Hawaii-Hilo
[email protected] E R I C I K S O O N I M Truong Dai hoc Hawaii-Hilo
eim@hawaii,edu
Ngiy nhan' 02/12/2013 Ngiy nhan lai
24/12/2013 Ngiy duyet dang:
31/12/2013 Ma so:
12-I3-DE-03
TiJ khoa:
Thien tai. ho gia dinh. thu nhap binh quar dau ngiroi.
dau Iir nha o. noi thuemg Keywords;
Natural disasters, households, per capita income, residential investmenl, domestic trade.
Tom tat
Bai viet danh gia tac dpng ciia thien tai doi vdi thu nhap binh quan dau nguai ciia cac ho gia dinh, dau tu nha a, va hoat dpng noi thirong a VN thong qua phan tich so lieu vl thien tai tii desinventa net va s6 lieu v l cac bien khac cho 64 tinh thanh tir T6ng cue Th6ng ke VN (2002-2011), Cac yeu to thiet hai bap gom: S6 nguai tu vong, s6 ngum bl thircmg, SP luong nha bi tieu hiiy va hu hong. Kit qua nghien CUT! cho thay thien lai khong co tac dpng dang kk tdi thu nhap binh quan dau ngiroi nhung co tac dong dong biln voi diu tu nha 6 va hoat dong noi thuong 6 VN Bai viet cung so sanh va dfii chilu nhung t6n that do thien lai theo cac viing a VN
Abstract
Using disaster data from the desinventa.net and data on other variables for 64 sub-regions from the General Statistics Office of Vietnam (2002-2011), we examine the impacts of natural disasters on household per capita income, residential investment, and domestic trade. The damage measures comprise the number of people killed, number of people injured, number of houses destroyed, and number of houses damaged. The results reveal that the aggregate effects of the disaster damages on household per capita income are insignificant and on residential investment are positive. We then compare and contrast the costs of disasters among different regions in Vietnam.
Phat triln Kinh tl 279 (01 /2014) | 23
1. GIOI THIEU
Tinh trang ndng len ciia loan cau hien nay va hau qua lam thay ddi hinh thtjc va mirc do thien lai gay quan ngai cho cac nha nghien ctiu va chinh quyen cae nudc tren the gidi. Tuy nhien, sd lugng nghien ciiu do ludng lac dgng ciia thien tai cdn il, nhk la nghien cim ve mdt nudc cu the. VN cd the lam diln hinh cho mdt nudc thudng bi bao nhiet ddi, cd bd bien dai va mtjc dau tu nha d kha ldn. Lich sir VN cung cho ihay siic chju dung dang ngac nhien ciia dan tdc trong eudc chien chdng thien tai va ngoai xam vi da quen vdi cac nghich canh "mau trgn biin non, com ehan nudc mat." Cac phuong tien thdng tin nudc ngoai cung ca nggi ngudi dan VN trong viec phdng chdng thien lai.
Thyc te nay khien chiing ta ban khoan ly hdi lieu nhirng cd gang khdng met mdi ciia ngudi Viet cd mang lai dugc hieu qua gi dang ke trong eude chien chdng lai su khac nghiet ctia ty nhien hay khdng; trong khi nhieu nudc khac da chimg minh ket qua hdi phijc dang ke cua hg nhu Nhat, Trung Qudc, v.v.. Bai viel nay mudn lim mdl giai dap cho cau hdi tren.
Khac vdi nghien ciru ciia Noy & Vii (2010), irong dd cac lac gia nghien cuu lac ddng vT md ctia thien tai len tdng san lugng qudc gia d VN va sir dung chi mdt phucmg trinh udc lugng, bai viel nay nghien cti'u lac ddng vi md eiia thien lai ddi vdi thu nhap binh quan dau ngudi ciia hg gia dinh, dau tu nha d va muc ban le hang hda trong ndi thuang d VN - ap dung he phuang irinh nhieu an sd. Sir dung so lieu thien tai tir mang desinventa.net va sd lieu cac bien khac cho 64 tinh thanh lir Tdng cue Thdng ke VN, lac gia udc lugng lac ddng cita thien tai len eae hp gia dinh trong ca nudc. sau dd lien hanh so sanh va ddi chieu nhirng ldn that do thien tai lai cac viing khac nhau d VN.
VN dugc chia Ihanh 8 vimg Idn, cac viing nay lai dugc chia nhd thanh 64 linh thanh.
Bang 1 the hien tan sd ihien tai trong giai doan 2002-2011 theo so lieu lir mang desinvenlar.net. Bang nay cho thiy thien tai xay ra nhieu nhat d mien Trung nhung cQng xay ra kha Ihudng xuyen d nhung viing khac, Dac diem nay ngu y viec diing sd lieu cho 64 tinh thanh la hgp H.
2 4 I Vu Bang Tam & Eric Iksopn Im | 22 - 40
B a n g 1. T a n s o t h i e n tai t r o n g t a m v i i n g a V N giai d o a n 2 0 0 2 - 2 0 1 1
Viing Dong bang song Hong Dong Bac Tay Bac Bac Trung 8 6 Nam Trung Bo Tay Nguyen Dong Nam Bo Dong bang song Cuu Long Tong so
So lu'ong 20 68 28 104 80 22 36 56 414
Tri so t r u n g binh
2,0 6,8 2,8 10,4 8 2,2 3,6 5,6 41,4
Do lech chuan
2,11 7,55 2,70 7,11 5,96 1,87 2,68 6,59 35,72 Ghi chii; Tri so trung binh bieu thi so luong thien tai trung binh trong mot nam.
Nguon: desinventar.net
Biing 2. C a c loai thien tai t r o n g 8 v i i n g & V N giai d o a n 2 0 0 2 - 2 0 1 1 Viing Bao Lu lut Benh dich Han han Sat to dSt Cac loai khac T6ngs6
I 3 64 1 4 25 4 3 102 6 5 79 2 1 21 2 5 34 6 4 53 Dong bang
song Hong Dong Bac Tay Bdc Bac Trung Bo Nam Trung Bo Tay Nguyen Dong Nam Bp Dong bang song Cuu Long
4
31 10 44 32 7 7 8
6
24 8 42 28 8 10 22
Tong so
Ghi chii: Cac loai khac bao gom mua da, thai tilt khSc nghiet va cac sir kien bat thuong .\gudn- emdat be
Phat triln Kinh te 279 (01.'2014)| 25
Bang 2 the hien cac loai thien tai xay ra trong giai doan 2002-2011 theo sd lieu tir mang emdat.be. DiJ lieu cho thay sd lugng bao nhiet ddi va lii lul nhieu gap bdn lan cac loai khac. Nhin chung, cd 414 thien lai trong bang sd lieu lai tir mang desinventa.net nhung chi cd 395 thien lai trong bang sd lieu tai tir mang emdat.be. Ngoai ra. VN khdng phai ddi mat vdi nhung Ihien tai cue idn nhu cac Iran ddng dat d Trung Qudc va Nhat, Dac linh nay giiip cho viec udc lugng it chju sai leeh do anh hudng ciia cac sieu su kien.
2. CAC NGHIEN CUU THlTC NGHIEM LIEN QUAN
Cac nghien cii'u lien quan den bai viet dugc chia lam ba nhdm chinh, Nhdm thii nhat bao gdm nhirng nghien ciJU phat trien vi md d ndng Ihdn trong viec ddi phd \di nhirng thay ddi bat ngd ve thu nhap va kha nang ciia cac hd gia dinh trong viee phdng chdng nhting bien ddng ay. Nhdm nay tap trung nghien ciiu phan img ciia cac ho ndng thdn Irudc mua lu hoac han han d eac nudc dang phai tricn nen cd lien quan den phirang phap liep can vi md ciia bai nay. Paxson (1992) sir dtjng diJ lieu chudi thdi gian \ e mua lii kel hgp vdi du' lieu cheo ve thu nhap ndng hg de nghien ciin tac ddng ctia loai thien tai nay Icn thu nhap gia dinh Tac gia phat hien mua lu gay lac ddng nghich bien len thu nhap nhung khdng gay tac ddng len inti'c chi lieu gia dinh. Han nua. mua lii chi cd tac dpng len Ihu nhap ngan han ma khdng gay tac dgng dang ke len thu nhap dai han.
Nhdm thil hai tap trung nghien ciiu tac ddng vT md ciia thien tai. Albala-Bertrand (1993) cho th5y thien tai lac dpng ddng bien len GDP nhung tac dgng nghich bien len thuong mai va tai khoan vang lai. Tac ddng dong bien len GDP dugc cho la do ddng d§u tu lang len sau thien tai de bii dap eho tai san hi pha hiiy. Skidmore & Toya (2002) ggi hien tugng nay la "pha huy tao tac" luong tu nhu khai niem duac Schumpeter (2008) gidi thieu, trong trudng hgp nay ham >' rang -pha hii\ dan ldi gia lang dau tu", Khai niem nay cd lien quan ldi bai viel vi mdt trong cac bien Irong bai la dau lu nha d eiia cac hg gia dinh,
Khac vdi cac nghien cuu ki tren. trong nghien ciru nay lac gia sir dung phuang phap ude lugng dan gian bSng each kit hgp kT thual hieu img cd djnh binh phuang nhd nhal ba giai doan (Fixed i^ffcct Three-Stage Least Squares/FE3SLS) vdi phuong phap he thdng hda irdc linh dilm Blundell-Bond (System Generalized Method of
\1omcnts/SGMM) dl kilm soat hicu img phan hoi giira cac bien va su hien dien ciia cac biln tre. Man nu'a. bai vicl sir dung so lieu ve hd gia dinh trong tat ca khu vyc thay
26 I Vu Bang Tam & Eric Tksopn Im | 22 - 40
vi gidi han trong khu vyc ndng nghiep nhu trong nghien ciiu Paxson (1992) hoac so 1 ieu vT md cua Albala-Bertrand (1993).
Nhdm thu ba nghien eiiu thien tai Irong mdl nudc nen cd iien quan tdi bai viet.
Horwich (2000) phan tich lac hai ciia Iran dpng dat Kobe nam 1995 d Nhat. Tac gia cung cap thdng tin ve Kobe 19 thang sau thien tai va riit ra bai hgc cho cac nudc khac.
Ong nhan manh lam quan trgng cua dau Or nhan luc trong phat trien kinh te. Tat ca tai san vdn bi hiiy hoai deu dugc khdi phuc nhanh chdng khi yeu to eon ngudi dugc bao ve va chuan bj kT eang.
Selcuk & Yeldan (2001) cung quan sat mdt thien tai lai mdt nudc cu the (Tran ddng dal nam 1999 d Thd NhT Ky)- Hg cho rang tac dpng ban dau cQa tran dgng dSt len GDP dtrong khoang-4,5% ldi+ 0,8% GDP, phu thupc vao cae ehinh sach dugc chinh quyen hoac cae nha lai trg qudc le Ihyc thi. Cae tac gia ggi y chinh sach tdi im la giam thue gian tiep bang each chinh phti trg cap cho cac thanh phSn kinh tl lu nhan dl khdi phuc tai san bj pha huy va lam giam tac ddng lieu cue ciia Iran dpng dal.
Halliday (2006) sii dung du' lieu bang ve ngudi lao dpng va ho gia dinh di dan lii El Salvador ldi My de kiem nghiem tac ddng ciia Iran ddng dal nam 2001 len mii'c di cu sang My, Ong phat hien Iran ddng dal lam giam lugng ngudi di cu tdi My: Xac suat trung binh cho mij'c di cu len phia Bac giam 37.11% cho moi do lech chudn do ludng mirc thiet hai ciia Iran ddng dat. Tac gia ket luan viec giam di cu la mdt chien luge doi phd cua ngudi dan khi hg giQ- lao ddng d lai trong nudc de kh^c phuc hau qua cua thien tai chir khdng phai vi thien tai lam giam ngudn tai chinh danh cho viec di cu.
Nhin chung. cac nghien ciiu deu ket luan lac ddng ciia thien tai co tinh ngSn han, va quan sal nay dugc tan dung trong bai viet. Tuy nhien tac gia udc lugng tac ddng ciia mgi thien lai xay ra d VN trong ca giai doan 2002-2011 Ihay vi mdt sy kien va quan sat hau qua v i md len thu nhap binh quan dau ngudi cita cac hd gia dinh, dku tu nha d, va doanh sd ban le trong hoal ddng ndi thuang a VN.
3. DU LIEU VA PHUGfNG PHAP NGHIEN CUU 3.1. Dii' lieu nghien cii'u
Dir lieu dong vai trd quan trgng trong nghien cuu thien lai nen bai viet luan theo quy Irinh trong Noy & Vu(20i0) nh^m phan lich dir lieu Irudc khi gidi thieu mdhinh. Du lieu ve thien tai va hau qua d 64 tinh thanh cua VN trong giai doan 1992-2011 dugc tai lir mang •'He thdng bang ke thien tai/He quan li thdng tin thien tai" (desinventar.net)
Phat triln Kinh tl 279 (01/2014)| 27
do Van phdng giam thieu nii ro thien tai thupc Lien Hiep Qudc. Mdt bd diJ lieu khac cung dugc tai tir "Ca sd dii lieu ve cac su kien khan cap" (emdat.be) dugc Trung tam nghien cim dichte hgc do thien tai (CRED) giai doan 1953-2012. Tuy nhien, dir lieu tir mang emdat.be la cho tirng sy kien ed the gay anh hudng ldi nhieu viing trong khi so lieu tir mang desinventar.nel thu thap hau qua gay ra eho tirng tinh trong 64 linh thanh, tao dieu kien ket hgp cd hieu qua vdi dir lieu ve cac bien khac cung cho 64 linh thanh.
Vi vay tac gia sir dung bd dir lieu tai tir mang desinventar.nel de lien hanh udc lugng.
Bp dii lieu nay khdng cung cap thdng tin ve thang xay ra thien tai nen tae gia khdng su dung phuong phap can ddi sd lieu dtja theo timg thang nhu trong Noy (2009) hoac Noy
&Vu(2010).
Bai viel diing bon yeu Id do ludng trong desinventar.nel de cau thanh bdn bien do mirc thiet hai {DMS): (1) Sd ngudi ttr vong {K1L)\ (2) Sd ngudi thuong lat {[NJ): (3) So lugng nha bj hiiy (HDE); va (4) Sd lugng nha hu hdng {HDA). Bd dir lieu tir mang desinventa.net cho VN con cd mdt sd ngudi bj anh hudng nhung chi bao gdm vai diem quan sat nen tac gia khdng dimg bien nay, Mol bien ke iren duae chia cho dan sd mdi tinh de cd dugc cac bien do ludng ti le thiel hai binh quan dau ngudi: KILP. INJP.
HDEP, va HDAP. Hinh 1 hiln thj thay ddi ciia bdn bien nay trong giai doan 2002- 2011.
Bang 3 ihl hien ba thien tai ldn nhSt trong giai doan 2002-20! 1 phan theo bon biln do ludng ke tren. Bang nay eung cho Ihdy dac diem quan trong ve thien tai d VN: Sieu su kien tuang ty nhu Iran dgng dat d Nhat hay Trung Qudc khdng xay ra d nudc ta. Vi vay sti dung dir lieu bang cho 64 tinh thanh la hgp li vi kel qua se it bi anh hirdng chech hudng do mgt vai dilm quan sat cijc ldn gay ra, Dtr lieu ve thu nhap binh quan dau ngudi cho cac hd gia dinh va dau tu nha d dugc thu thap lii- "Khao sal mirc sdng gia dinh VN" ciia Tdng cue Thdng ke VN (2002-2011). Sd lieu ehi cd cho nhirng nam chin tir 2002 - 2010. Tac gia linh loan so lieu eho cac nam le bang phuang phap trung binh trgng sd kit hgp dieu chinh xu hudng de cd dugc bd sd lieu hang nam cho giai doan 2002-2011.
2 8 I Vii Bang Tam & Eric Iksoon Im | 22 - 40
H i n h 1, B o n b i e n d o lircmg m i i c thiet hai d o thien tai ff V N g i a i d o a n 2 0 0 2 - 2 0 1 1 30 - - - -
25 r-- - -
/\
20 -L ^—r
/ .
15 : , A \ / ' • • • - 10
• - IKLP - INIP
— HDEP
" • • H D A P
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 Ghi chir KILP = Ti ie ta vong binh quan dau nguoi
INJP = Ti le tliuang tat binh quan diiu nguoi IIDLP - Ti ie nha bi tieu huy binh quiin dau nguoi piDAP " Ti le nha hu hong blnh quiin dau nguoi Nguon' dcsmventar.net
B a n g 3 . Ba thien tai Iffn n h a t t r o n g moi loai giai d o a n 2 0 0 2 - 2 0 1 1
Tinh/Thanh Nam KIL(#) INJ («) HDES («) HDAIVl (#)
Phan theo so lu'ong nguoi tiivong
Quang Ngai 2008 325 Diing ThiSp 2006 150 Yen Bai 2009 145 301 316
24.143 21.324 19 243
45.248 35.454 51.233 Phan theo so luong nguoi thuong tat
Ba Ria-Vung Tau 2006 132 763 25 165 48.537 Bin Tre 2006 118 492 29.048 92.600 QuiingNgili 2009 127 348 23.187 49 275 Phan theo so luong nha bi tieu hiiy
c i n Tho 2002 Quang Tri 2009
275 165
52.011 42.058
Phat triSn Kinh tS 279(01/2014)1 29
Ben Tre 2006 Phan theo so lu'ong nha bj hu' hong
Quang Binh 2010 124 Bin Tre 20O6 118 Ha TTnh 2002 85 276 492 324
27.956 29 048 24 374
162.002 92.600 53 210
Ngudn: desinventar.nel
Viec tao dung sd lieu cd the cho kel qua it nhieu sai lech nen tac gia cung tien hanh udc lugng vdi bd diJ lieu gdc cho eac nam chan de kiem djnh muc chinh xac ciia kel qua udc lugng.
Sd lieu ve thu nhap binh quan dau ngudi dugc cung cap theo thang va theo gia hien hanh. Tac gia nhan cho 12 thang dl thu dugc so lieu hang nam va ddi sang gia cd djnh nam 1994 dua theo chi sd gia ca lieu diing (CPI). Sd lieu hang nam ve ngudn vdn cho 64 linh thanh dugc Ihu thap lii' bd sd lieu "Cac chi lieu tdng hgp phan theo tinh, thanh pho va viing lanh tho" va so lieu ve cac biln khae dugc thu thap tii Nien giam thdng ke; ca hai diu do Tdng cue Thong ke VN cung cap. Bang 4 the hien thdng ke md ta cho cac bien khac diing trong bai nay.
Bang 4. Thdng ke nid ta cho cac bicn khac
Bi^n Thu nhap binh quan dau nguoi Nguon von
Van chuyen h^ng hoa So hoc sinh nhap hoc Dau tir nha a Doanh so b^n le So nhan vien y te Dan so Lai suat thuc
Bon vj Nghin VND
Tl VND Tan*l<m 1 000 hoc sinh m-/d,"tu ngiroi
TiVND Nguoi 1.000 nguoi
•70
Tri so Irung binh
9.510.403 102.867 22 057 125 284 15.6 98 272 3 978 79.124 3,25
i)6 lech chuiin 345 1 546
804 2.523 5.27 8.901 136 1.019 1.67 Ghi chii: Tn s6 trung binh bilu thi gia tn trung binh mot n3ni
30 I va Bang Tam & Eric Iksoon lm | 22 - 40
Sd lieu hang nam vl ngudn von cho giai doan 2000-2008 thi cd sin. Vi ngudn von thudng bilu thj tac ddng dai han nhu dugc phan lich trong Barro & Sala-i-Martin (2004), bai vilt se six dung so lieu ngudn vdn cho bien tre trong md hinh. De tao bien dai dien cho dau lu nhan luc, tac gia cdng gdp hgc sinh tir lieu hpc, trung hgc, cao dang va dai hgc dl dugc long sd hgc sinh trong ca nudc. Sd lieu ve tdng sd nhan vien nganh y tl dupc sti' dung lam dai dien cho cham soc sire khde. So lieu ve van chuyen hang hda dugc diing lam dai dien cho ca sd ha tSng. Cac sd lieu diing gia hien hanh dugc chuyen doi sang gia cd djnh dya theo chi sd gia tu lieu san xuat (PPI).
So lieu vl doanh sd ban le dugc diing lam biln dai dien cho bien ngi thuong va cung dugc chuyen doi sang gia cd djnh cho nam 1994 dya theo CPI. Tat ca nhirng bien tren dugc chia cho dan sd de thu dugc do ludng binh quan dau ngudi. Sd lieu ve lai suat thuc {RJNT) dugc thu thap tii- Thdng ke tai chinh qudc le (International Financial Statistics) do IMF cung cap. Tac gia tao bien tuong lac bang each nhan bien RINT\6i cac bien gia cho mdi linh thanh de phan biet su khac nhau trong thi trudng tai chinh, vai trd ciia nha nudc trong viec quan li lai sual va lac ddng cua ngudn lin dung trong moi tinh thanh. Sd lieu hang nam cho cac bien nay cd tii'2002 -2010. Tuy nhien cd mpt sd nam bj thieu mdt vai diem quan sat nen tac gia sir dung bien gia nhj phan de han che nhung dii' lieu bj thieu.
3.2. Phuong phap nghien CIJU
De phan anh kha nang tuang lac giira cac bien, mpt he phuang trinh dugc udc lugng ddng loat:
Y,, =a^DMS,,+a.,DMS,,_, +pX,, +q, +s, +e,, (1.1) ENDO,, ^ id^MS,, + K.DMS + (l>Z,, +v, + w; +(o^, (1,2) Trong dd: DMS bieu ihj nhiing tdn that do ihien lai gay ra; Y la thu nhap blnh quan
dau ngudi, X la \ ecta ciia cac bien kiem soat, ENDO bilu thj vecto ciia cac biln ngi sinh gay hieu ting phan hdi hoac cd van de ve do ludng va Z la vecta cita cac bien anh hudng den bien ndi sinh. Ba bien cudi la cac sai sd vitng, thai gian va sai sd rieng biet (/ va I). Md hinh chi bao gdm mdl bien Ire cho DMS dl phan anh ket qua vl tinh ng^n han cua nhiing tac ddng do thien tai gay ra trong nghien cuu duang thdi. Kilm djnh VIF nhu dugc gidi thieu irong Kennedy (2008) dugc ap dung dl phat hien hien tugng da cdng tuyen. Sau vai vdng loai bd cac bien cd da cgng tuyen cao va thuc hien kiem
Phat triln Kinh tl 279 (01/2014)1 31
djnh Granger de phat hien mdi quan he nhan qua, tae gia thu dugc he phuang trinh (2) gdm ba phucmg trinh cau trtic:
};_, = a , DMS,,+a^DMS,,_, +f3,CAP,,_^ ^p^INIT^, +pJNFR^, +q, +s,+£,, (2.1) INV,, ^e^DMS,,+e^DMS,,_^ +A^TRAD^,+A,RINT^,++;i^Y,, +t,+u,+<p^, (2.2) TRADE,, =KDMS,, +K^DMS,,_, +^INV,, +/JJNFR,,V, +W, +CO,, (2.3)
Trong do: CAP bieu thj ngudn vdn, INIT la thu nhap ban dau, INTRA ca sd ha tang, INV dau lu nha d, TRADE ndi thuong (doanh sd ban le), and PINT lai suat thyc.
Quan sal he phucmg Irinh nay cho thay thu nhap blnh quan dau ngudi khdng gay lac dpng ngugc lai len ton that do thien tai (DMS). Tuy nhien kiem djnh Hausman dieu chinh nhu dugc gidi thieu trong Kennedy (2008) cho thay DMS van gay ra hien tugng npi sinh, cd kha nang do sai sd do ludng. vi vay bien cdng cu cho DMS can dugc sir dung citng vdi cac bien cdng cu cho Y, INVva. TRADE. Do hien tugng phan hdi giira cae bien trong he (2), phuong phap hieu img cd djnh binh phuang nhd nhal ba giai doan (FE3SLS) dugc su dung de udc lugng he nay. Trong udc lugng du lieu cheo. rat khd tim dugc bien cdng cy, Trong udc lugng dii' lieu bang, bien tre ed the sir dijng lam bien cdng cu. Do vay hinh thuc riit ggn cho he (2) la he (3) dudi day:
DMS,,=7r,,DMS,,_,+/i,.CAP,,^^.,+7r,,lNFR,,+e^,, (3.1)
^,.1 =^2\y..,-\ +^2i^^S,,-x +^2,INFR,, +/r,,CAP,,_^+c,,, (3,2) INV,, = TiyJNV,,,, +/r^,DMS,,_^ + n^^RlNT,,+e,,, (3,3) TRADE,, = Ti^JRADE, ,_^+ 7T,.DMS, ,.^+ TT^JNFR,, + c,,, (3,4) D I khSc phuc hau qua ctia bien tre phu thugc. phuang phap he thdng hda udc tinh
dilm Blundell-Bond (SGMM) nhu phan tieh trong Bond (2002) dugc su dtjng va kel qua udc lugng cho DMS, Y, INV. va TRADE dugc dimg lam bien cdng cu trong udc lugng FE3SLS cho he (2). Giai thich chi tilt cho phuang phap SGMM dugc irinh bay Irong phan phu luc.
4. KF.TOUANGHIE^ CUU
Bang 5 trinh bay kit qua hdi quy cho lac ddng tdng quat ciia bdn ldn that thien lai d VN, Do sy hien dien ciia biln tre, tdng so ciia bien hien tai va bien tre dugc ii'nh toan, sau dd kilm djnh cho y nghTa thdng ke ciia cac tdng sd dugc tien hanh. Thi du. ldng gia
32 I VO Bang Tam & Eric Iksoon lm j 22 - 40
trj hien lai va gia tri Irl cho bien "Tir vong" trong Bang (5a) la - 0.1091, ngu y neu li le tir vong trong dan so tang I %, thu nhap binh quan d^u ngudi giam 10.910 VND, va gia trj p - 0.476 xac djnh he so udc lugng khdng cd y nghTa thdng ke. Cac bien khac dugc tinh loan theo each thu'c tuang nr. Kit qua tir Bang (5a) tiet Id ca bdn tdn that khdng lac ddng tdi thu nhap binh quan dau ngudi trong cac hd gia dinh.
Bang (5b) trinh bay tac ddng long quat ciia bdn tdn that thien tai len dku tu nha d:
Hau hit cd tac dpng ddng bien va cd y nghTa thdng ke. trir Irudng hgp ti le thuang lat CO lac ddng nghjch biln. Tdng ciia cac gia trj hien tai va gia trj Ire cung dau vdi bien hien lai va diu cd y nghTa thdng ke. Thi du. tdng cita gia trj hien tai va gia trj tre cho biln "Tu vong" trong Bang (5b) la 2.8066. ngu y niu ti le tii' vong trong dan sd tang 1%, dau tu nha d tang 2,8066 m^, va gia tri p - 0,037 xac djnh he sd udc lugng co y nghTa thdng ke it nhat d mti'c 5%, chinh xac d mii'c 3,7%. Cach tinh cho cac bien khac luong lu nhu tren.
Kel qua long quat cho Ihay lat ca cac lac dgng deu ngan han. luong ddng vdi ket qua Irong nghien cii'u hien cd, Tac ddng ddng bien Irong Bang (5b) va khdng cd y nghTa Irong Bang (5b) ngu y cac nudc dang phat trien ndi chung va VN ndi rieng cd sii'c hoi phuc kha nhanh chdng. Vi tich luy dau tu dan den tang nguon vdn, va ngudn vdn lac dpng len GDP, kel qua ciing ngu y dau lu nha d cd kha nang gian liep day liii tac dgng CO the la nghjch bien len thu nhap binh quan dau ngudi. Ket qua nay cung hd trg cho thuyet "pha hiiy dan tdi gia tang dau lu" trong Skidmore & Toya (2002).
Bang (5c) cho thay ca bdn tdn that Ihien lai deu cd lac dgng nghjch bien va cd y nghTa len ndi thuong, khang djnh ket qua luong lu trong nghien ciiu hien thdi d muc vT md. Thi du. ldng gia tri hien tai va gia trj Ire cho bien "Tir vong" trong Bang (5c) la -2,7593, ngu y neu ti le tCt vong trong dan sd lang 1%, muc ban le hang hda trong hoat ddng npi thuang giam 2.7593 trieu VND. va gia trj p = 0,039 xac djnh he sd udc lugng cd y nghTa thdng ke d mii'c 3.9%.
Phan tich trong Greene (2003) va Wooldridge (2003), he sd R^ dilu chinh trong cac udc lugng sir dung bien cdng cu khdng cung cap thdng lin cd y nghTa. Thay cho he so R- dieu ehinh, phan mem kinh le lugng STATA su dung trong bai vilt cung cap can nguyen sai sd binh phuong (Root Mean Square Error/RMSE) dugc bao cao trong moi bang '''. Gia trj nhd ciia RMSE ngu >' md hinh udc lugng phii hgp kem theo gia tri p cho md hinh nhd hon 0.05.
Phattriln Kinh tl 279 (01/2014)1 33
Do tac ddng cua tdn that ihien lai len dau tu nha d va ndi thuang cd y nghTa thdng ke, bai viet di sau vao nghien curu nhirng tac dpng nay len timg viing d VN. Ddng bang sdng Hdng cd tan sd thien tai thap nhat nen dugc chpn lam nhdm co sd, 7 bien gia cho do ddc ciia dudng hdi quy dugc kien tao cho 7 viing cdn lai. Bang 6 va 7 the hien lac ddng ciia 4 tdn that thien tai len dau tu nha d va hoat ddng ndi thuang d mdi vitng. He sd Clia nhdm co sd dugc cdng vdi he sd ciia mdt nhdm khac va kiem djnh cho miic y nghTa cita mdi long sd dugc tien hanh va ghi nhan trong hai Bang 6 va 7,
Bang 5. Tac dong tdng quat cua bon ton that thien tai d VN Bang (5a) Bien phu thuoc:
DMS,
DlV1S,.i
DMS,
CAP
INFR
INIT Biln
1 D M S M
Bang(50.b) Bien phu thui DMSt
DMSl- 1
Thu nhap binh quan T i i v o n g
0,0014 (0,153) -0,1105 (0,459) -0.1091 (0.476) 0 , 3 6 9 5 « "
(0.000) 0.0006*
(0.076) -0.0003**
(0,048) )c; Ban tu' nha o binh
3 . 4 9 9 * "
(0.000) -0,6824 (0.206)
dau nguoi cho i T h u o n g tat
-0.0002 (0,697) 0,0004 (0.650) 0.0002 (0.658) 0 . 3 6 9 6 " '
(0.003) 0.0007*
(0.083) -0.0004**
(0.039) quan dau nguo
-1,728***
(0,009) -0.5825 (0.174)
[•ac ho gia dinh N h a b i tieu hiiy
0.0002 (0,991) 0,0001 (0.592) 0.0003 (0.508) 0.3694***
(0.000) 0.0005*
(0.069) -0.0004**
(0.042)
0.3943***
(0.003) 0.0336 (0,235)
N h a b i hu' hong
0.0001 (0,315) -0,0002 (0.586) -0.0001 (0.723) 0.3697***
(0.001) 0,0008*
(0,091) -0.0003**
(0.034)
0.7307***
(0.000) 0,0238 (0,586)
34 I Vu Bang Tam & Eric Iksoon Im | 22 - 40
DMSt + DMS t-1 2.8066"
(0,037) 0,9230***
(0,006) -0,4029**
(0,034) 0.0325**
(0,048) so ban le binh
•2,969***
(0.003) 0,2097 (0,651) -2.7593**
(0.039) 1,073**
(0,027) 0,1457***
(0,007)
- 2 , 3 1 0 5 "
(0,029) 0,3245**
(0.019) -0,4073***
(0,007) 0,0287*
(0,063) quan dau ngui
-2,083***
(0,001) -0,7478 (0,315) -2.7308**
(0.049) 0,9353***
(0,009) 0.0412**
(0,035)
0,4279**
(0,041) 0,5178***
(0,009) -0,4471**
(0,045) 0 , 0 4 1 2 "
(0,037) j i
-0,4124***
(0,000) 0,2451 (0,412) -0,1673**
(0.021) 0,6987***
(0,000) 0,1051**
(0.026)
0,7545*' (0,043) 0,7549"^
(0,000)
•0,3950**
(0,004) 0,0289*
(0,084)
-0,3602**
(0,002) -0,0188 (0,561) -0,3780**
(0,033) 0,7017**'
(0.001) 0 , 2 1 5 l * "
(0,004) DMSl + D M S M
C P mau, 448, Trj s6 RMSE trung binh cho toan he, 0,3254; gia tri p cho mo hinh: 0.002;
Gia t r i p cho kiem dinh White: 0.534: gia tri p cho AR(1): 0.214; gia tri p cho AR(2): 0,857.
Ghi chii: ***. * ' . * bieu thi muc y nghTa 1%, 5%, va 10 %, theo thii tu tuong img; gta tri p hien thi trpng ngpac don. Quan sat Bang 6 cho thiy hau het cac viing co tkn s6 thien tai cao khong co mite dau tu nha d cao hon cac vimg khac. Ket qua vi mp nay tuong tu nhu kit qua vT mo vh t6ng san Iirpng qupc gia va tang trudng kinh t l trong Npy & Vii (2010) vi tich luy dSu tu la ylu t6 quan Irgng trong sin xuat, Trong giai dpan 2002-2010, chi co yiing Dong Nam Bo la co he s6 udc luong cao hon nhom co sd. nhung viing nay lai xep thii 5 ve tan s6 thien tai va co miic phat tnen cao hon cat viing khac. Phat hien nay ho tro chp quan sat Uong Cuaresma & cpng su (2008) Nhirng viing co chi so phat irien cao CP kha nang nang cap nguon von nhilu hon sau m6i thien tai.
Phat trien Kinh te 279 (01 /2014) j 35
Bang 6. Tac dong cua thien tai len dau tir nha ir cho timg viing d VN Bien phu thuoc: Dau ttr nh:
Bien
Dong bang song Hong
Dong Bac
TSy Bac
Bac Trung Bp
Nam Trung Bo
Tay Nguyen
Dong Nam Bp
DBSCL
TRADE
RINT
Y
a a binh quan Tu- vong
3,846***
(0,003) 3,163**
(0,035) 2,943**
(0,047) 2,525**
(0,027) 2,717**
(0,036) 3,235**
(0.042) 6.425***
(0.005) 3,057**
(0,026) 0,9652***
(0,009) -0,3293**
(0,049) 0,0412*
(0,071)
dau nguoi
Thirong tat
8,791**
(0,026) 6,573**
(0,018) 5,326**
(0,048) -5,248**
(0,025) -4,972**
(0.033) -3,716**
(0,028) 9.634***
(0,004) - 4 , 4 4 7 "
(0,027) 0 . 6 1 0 6 " *
(0.005) -0,3196*
(0.059) 0,0326**
(0,024)
Nhabi tieu hdy 0,2597**
(0,032) 0,3831***
(0.002) 0,2930**
(0,043) -0,1901**
(0,028) -0.4627**
(0,018) 0.2867**
(0,035) 0.5934***
(0.000) 0,2136 (0,048) 0.5256***
(0.000) -0.2497*
(0,093) 0.0398*
(0,085)
Nhabi hirhong 0,7876***
(0,000) 0 , 6 7 2 9 * "
(0,002) 0,7231**
(0,023) -0,6371***
(0.009) - 0 . 7 1 9 8 "
(0,049) 0,2316**
(0,039) 1.0862"
(0.044) 0,5743**
(0,036) 0.7482***
(0.000) -0,2993***
(0,004) 0,0289*
(0,094)
36 I Vu Bang Tam & Enc Ikspon Im | 22-40
Co mlu: 448; trj s6 RMSE Uung binh cho loan he: 0,4648; gia tri p cho mo hinh: 0,000, Gia Ul p cho kilm dinh White: 0,734; gia tri p cho AR( 1): 0,198; gia tri p cho AR(2): 0,649, Ghi chu: ***, **, * bilu thi muc y nghTa 1%, 5%. and 10 %, thep thiJ ty tuong iing; gia Ui p hien thi Upng ngpac don.
Bang 7 cho Ihay tac dong ciia thien tai len hoal ddng npi ihuang thay ddi dang ke Iheo vitng. Them mdl dac diem nua dang luu tam: Nam Bd chju hau qua nhe han rat nhieu so vdi Bac bd, Dieu nay chq thay mien Nam cd kha nang phuc hoi budn ban sau thien tai nhanh han mien Bac. Tham chi ndi thuang d nhung viing it phat Irien nhat d phia Nam nhu Tay Nguyen hay Ddng bang song Ciru Long ciing chju lac ddng it nghiem Irgng han so vdi cac viing d mien Bac.
Bang 7. Tac dgng ctia thien tai len hoat dong ngi thuoTig cho tung viing d VN Bien phu thupc:
Biin DB song Hong
Dong Bac
Tay Bac
Bac Trung Bo
Nam Trung Bp
Tay Nguyen
Dong Nam Bo
DBSCL
Doanh so ban le blnh
Tu-vong
-4.901***
(0.000) -4,823**
(0,038) -4,282***
(0,003) -5,287**
(0.022) -2,289**
(0,016) -2,534**
(0,046) -1.454***
(0,001) -1,559**
quan dau nguoi
Thuong tat
-4,185***
(0,000) -2,475***
(0.000) -2,933**
(0.015) -4.632**«
(0,001) -1,375***
(0,003) -1.163**
(0,024) -1.248***
(0,004) -1,073**
Nhabi tieu hiiy -0,9452***
(0,006) -0,9159**
(0.032) -0,9832**
(0.031) -0,8985**
(0,027) -0,0956**
(0,048) -0,4738***
(0,001) -0.2135**'
(0.000) -0.2247***
Nhabi hu- hong -0,4284***
(0,000) -0,4329***
(0.001) -0,4825**
(0,046) -0.3956***
(0,003) - 0 , 2 1 1 2 "
(0,045) -0.2097**
(0.042) - 0 . 1 2 1 8 "
(0.041) -0,1648**
Phat tnen Kinh te 279 (01/2014)1 37
(0,046) 0,0719***
(0,002) 0,1246***
(0,000) -0,1078**
(0,032)
(0,022) 0,0833***
(0,005) 0 , 1 2 3 2 "
(0.019) -0,1134**
(0,025)
(0,001) 0,0786***
(0.000) 0,1185***
(0,000) -0,1056**
(0,018)
(0.045) 0,0901 **•
(0.001) 0,1248**'
(0.007) -0,1213*'
(0.041) Co mail' 448; tn so RMSE trung binh cho toan he' 0,3867; gia tn p chp mo hinh: 0,001;
Gia Iri p cho kiem dinh White- 0,476; gia tri p cho AR(1): 0,203; gia tri p cho AR(2)- 0,749.
Ghi chu: ***, **, * bilu thi miic y nghTa 1%, 5%, and 10%, theo thu tu tucmg ung; gia tri p hien thi trong ngoac don.
Sau ciing, tac gia lap lai cac ude lugng ke tren sir dung sd heu gdc cho cac nam chSn va thu dugc ket qua tuang lu ve dau, dp ldn va y nghTa thdng ke. luy nhien kel qua kiem djnh cd gia trj p bien dgng kha nhieu liiy theo mdi do ludng ldn that. Ket qua nay dupe cung cap Iheo yeu cau va khdng cd gi dang ngac nhien vdi phuong phap FE3SLS: ed mau cang ldn cang mang lai kel qua kiem djnh nhal quiin hon.
5. GOI Y CHiNH SACH
Dya tren kel qua udc lugng. mdl vai ggi y chinh sach dugc kien nghj nhu sau. Thir nhat, miic phat trien ciia mdi viing ddng vai tro quan trgng trong viec giam thiet hai do thien lai gay ra qua dau lu, do vay VN can lang cudng lai trg tir cac quy lir thien trong va ngoai nudc cho viec xda ddi giam ngheo va lam tang cae chi sd phat trien khac nhu giao due, y te va phue Igi xa hdi. Thti' hai, hoal ddng phdng chdng thien tai d VX thudng duac ngudi dan VN lien hanh kha lich cue va da giam dugc mdl phan ton that dang ke do thien tai gay ra, Cac cap chinh quyen trung uong va dia phuang cung cd gang rat nhieu trong \ iee so tan ngudi dan tdi vCing an loan trudc khi \a\ ra thien tai.
Tu)' nhien, tin tiic thu dugc vao ngay 18/11 ve can bao Hai Yen dd bp vao mien Bac thay vi mien Trung ngay 10/11 va hau qua sau bao van cho thay mpt so lugng tir vong.
ihuang tich va thiet hai tai san dang ke. Chinh quyen trung uang va dm phuang can tang cudng irg giiip ngudi dan viing thien lai, bao gdm cap nhal dy bao, thdng bao kip thdi. hudng dan kT lhuat va gitip dd ve nhan luc cho cdng tac phdng chdng thien lai
38 I Vu Bang Tam & Eric Iksoon Im | 22 - 40
Cudi cimg, budn ban giira cac tinh va trong ndi bd mdi tinh thanh phu thupc nhieu vao ha tang ca sd nhu dudng sa, cau cdng va phuang lien thdng tin, cac cap chinh quyen can gia cd cac ca sd ha tang trudc mdi thien tai va uu tien khdi phuc cap tdc he thong ha tang sau thien tai de cd the nhanh chdng ndi lai mang ludi giao djch cho cac hoat ddng ndi thuang.
Gidi han ve so lieu cho nhieu bien, thi du chi lieu cdng va lu cho cac hoat dgng phdng chdng thien tai, cd the lam cho kel qua thieu tin cay. Dac biet sd lieu ve thu nhap binh quan dau ngudi cho cac hp gia dinh chi cd cho cac nam chin va cd thi lam cho ket qua udc lugng tac ddng vi md mat tinh chinh xac. Ngoai ra, nghien cuu tac dpng CLia bdn ton that do thien tai gay ra tren mdi linh Ihanh hoac so sanh doi chilu giiJa thanh thj va ndng thdn cung la nhirng de lai hdp din va dugc danh cho nghien cuu tuong lai.
Ghi chii
[I] Duoc xac dmh la RMSE = / - X ( > ' i " X ) "
PHU LUC
Phirong phap he thang hoa uoc tinh diem (SGMM) cua Bond (2002) la mot ap dung nang cap cua phirong phap Arellano & Bond (1991) va Arellano & Bovei (1995) Arellano & Bond (1991) gioi thieu phirong phap sai phan irdc tinh diem (differenced GMM) cho cac mo hinh nang dong. Phirong phap diing de che ngu cac bien phu thupc tri dirpc xac djnh truoc nhimg khong hpan tPan ngoai sinh: chung cp linh dpc lap doi vdl sai s l hien lai nhung bi anh hirong boi sai s6 tre Diing phan sai cua cac biln phu thuoc tre hoac su- dung hinh thiic chuyen chech tir tn s6 trung binh se loai bp duoc hieu img co dinh. Tuy nhien phuong phap sai phan udc tinh diem gay ra he so thien lech va kiem dinh khong dang tin cay n^u bi^n npi sinh tuan theo budc ngau nhien Trong Irudng hop nay, gia tri tre cung c§p rdt it thdng tin ve thay ddi trong tuong lai nen bien Iri khdng dirpc chuyen ddi se la cdng cu y^u kem chp cho cac bi^n da duoc chuyen ddi.
De giai quyat van d l nay, Blundell & Bond (1998) gidi thieu mot phirong phap cai tidn cua phuong phap Arellano & Bover (1995) Theo dd, sai phan cua cac biln cong cu duoc ciu thanh khiln cho chiing trdthanh ngoai sinh doi vdi hieu ung c6 dinh, De cau thanh diroc nhung sai phan nay trong khi giir nguySn tinh trang ciia cac biln khac trong md hinh gdc Arellano-Bond, ho tap phuong phap he thdng hoa GMM
Phat trijn Kinh tS 279 (01/2014)1 39
'z'~
1 ' x]' X,
, irpng dd 2* la
, ;;; =
'Y''Y.
{system GMM) bang each nhan bo SP lieu gdc vdi ma Iran chuyen ddi Z^ =
tran dupc sai phan. Dp vay, chp mdi ca the i, bd sd lieu mdi tro thanh X,^ —
Khi mpt bien tuan theo budc ngau nhien, nhOng thay dpi trong qua khir co kha nang phong doan hien tai nhieu hon nhiJng thay ddi hien tai cd kha nang phdng dpan qua Ichii nen cdng cu mdi tSng them miic chl ngu SP vdi cdng cu gdc cho md hinh cd bien phu thudc tre. Do vay, phucmg phap Blundell-Bond (1998) che ngu co hieu qua hien tuong tu ntong quan, phuong sai thay ddi, cung cap he so udc lupng nhat quan va ket qua dang tin cay trong kiem dinh cho hien tupng tu tucmg quan va kiem dinh Sargent so vdl phuong phap Arellano-Bond (1991), Ticn hanh udc luong md hinh giam thieu trong he (3) su dung phuong phap Blundell-Bpnd GMM se giai quyet cd hieu qua nhung van de tiem an Irong mo hinh bao gdm biln tri phu thudc. Ket qua udc luang chp D\4S. ), INV. and TR.WE sau do duoc diing iam bien cdng cu trong FE3SLS cho he (2 ) •
T a i lieu t h a m k h a o
Albala-Bertrand, M. J. (1993), "Natural Disaster Situations and Growth: A Macroeconomic Model fpr Disaster Impacts," World Developmenl. 2\. 9, 1417-1434.
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Center for Research Epidemiology of Disasters (2013), Emergency Events Database, Imp,//emdat. be/
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Evidence from Developing Countries," Economic Inquiry, 46(2). 214-226.
Greene, W. (2003), Econometric Analysis. Fifth Edition Pearson Wesle\, Princeton, NJ Halliday T. (2006), "Migralipn, Risk and Liquidity Constraints m El Salvadpr," Economic
Developmenl and Cultural Change. .'^4(4), 893-925,
llprwich G, (2000), "Econpmic Lesspns pf the Kobe Earthquake," Economic Developmenl and Cultural Change. 521-542
Kennedy, P, (2008), A Guide lo Econometrics. Sixth Editipn, MIT Press. MA.
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Paxson. C. H. (1992), "Using Weather Variability to Estimate the Response of Savings lo Transitory Income in Thailand," -imencan Economic Review. 82(1). 15—33.
4 0 I Vij Bang Tam & Eric Iksoon lm j 22 - 40
Schumpeter, J. (2008), Capitalism, Socialism and Democracy, New York, Harper [original publication in English, 1943].
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