MOI QUAN HE PHI TUYEN GlfA THU NHAP VA THAM NHUNG TAI CAC NEN KINH TE CHUYEN DOI
Dang Van Cirdng*
N g a y nhan, 9/4/2015 N g a y nhan ban siia, 2/6/2015 N g a y duyet dang' 30/8/2015
Tdm tat;
Bdi viel ndy khdo sdt moi quan hi phi luyen giUa thu nhgp vd tham nhdng tgi cdc quoc gia cd nen kinh le chuyin doi. Vai miic tiiu ndy, nghien ciru dua vdo mo hinh biin binh phuang cua bien Ihu nhgp ciing voi viec kiem sodt cdc bien kinh te xa hoi vd khung the che cdc quoc gia. De ddnh gid he so hoi quy ciia cdc bien trong mo hinh, tdc gid su dung mo hinh hieu irng co dinh cho dir li$u bdng Bin cgnh do, de dam bdo linh vimg cho cdc uac luang, phuangphdp GLS vd 2SLS cung duac sic dung trong cdc kit qud uac lugng Kit qud nghien cuu chirng minh co su xual hien cm hi^u img phi tuyen trong moi quan he ndy. Nghia id, thu nhdp tdng lin se ldm ldng Iham nhung 6 giai dogn ddu cua thai ky chuyen doi, nhung sau do nen kinh le chuyen sang giai dogn phdt trien on dinh, tdng thu nhgp se giup gidm thieu ngn tham nhUng.
Til' khoa: Tham nhung; thu nhap; FEM; GLS; 2SLS.
The nonlinear relationship between income and corruption in transitional economies Abstract-
The paper examines the nonlinear relationship between income and corruption in the context of transitional economies. Therefore, the study adds squared income variable to the model and con- trols socio-economic and institutional factors. The author addresses the fixed effect model for panel lo obtain the coefficients of these regressors. Additional, GLS and 2SLS methods are also
used for robustness analysis of the estimation results. The findings demonstrate the existence of the nonlinear relationship. This implies that an increase in income will enhance corruption in the early stages of the transition period, but then the economy develops prosperously, rising income will reduce corruption.
Keywords- Corruption; income, FEM; GLS; 2SLS
1. Dan nhap hudng ciia tham nhung d cac quoc gia. Ket qua Do sy inh hudng tiau cyc din xa hpi, tir lau tham nghien ciiu nay da nhan dupc mgt vai sy ddng thuan nhiing da trd thanh chii de trpng tam trong cic ITnh nhimg ciing tdn tai khdng it cac y kien trai chieu.
vyc khoa hgc chinh tn vi kinh tl hpc, dgc biet la Kat qui ndi bat cua cac nghien ciiu nay cho thay trong bdi cinh cac qudc gia dang chuyen dii. Trong tham nhung chiu sy tic ddng tiau cyc tir tang trudng nhirng nam gan day, cic nghien cuu ve cac ylu td kitih tl d cic qudc gia, do do cac qudc gia giiu (thu tic dgng dan tham nhiing la rat da dang v i phong nhap binh quan diu ngudi cao) thudng dupc cam phu. Trong dd, ylu to thu nhap tac ddng din tham nhan la it tham nhiing hon d cic qudc gia ngheo (thu nhung dugc quan tam nhilu nhit trong cic nghien nhap binh quan diu ngudi thip). Tuy nhien, vin de Cliu thyc nghiem'. Nghian ciiu cua Graf Lambsdorff quan tam la tai mdt qudc gia dang chuyin ddi (quic (2005) da phat hien ra cac nguyan nhan va anh gia ngheo) tinh trang tham nhung cd thi dang d miic
sa 222 Ihing 12/2015 62 kinli li^liat trlCD
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cao, vay viec cai thien thu nhap cd lim giim tham nhiing ding ke hay khdng thi van chua cd cau tra ldi chae chan.
Mdt han che quan trpng cua cac nghien ciiu trudc day la chi tap trung vao viec danh gii hieu iing myen tinh ciia thu nhap Ien tham nhiing. Trong khi dd, khung ly thuylt ve mdi quan he giua tham nhiing vi tang trudng kinh te cua Dzhumashev (2014) cho thiy rang mdi quan he nay la khdng ddng nhat vi phiic tgp. Mdi quan he phi myan niy cung da dirge khang dinh trong md hinh Iy thuylt va ket qua thyc nghiem ciia Saha & Gounder (2013), tuy nhien, nghien cim niy chi sii dung phuang phap udc lugng PES (Pooled Least Square) cho dii lieu bang va chua KXX ly van de ndi sinh cd the ton tai trong md hinh nen ket qui cua nghian ciiu chua that sy dang tin cay^. Vi vgy, nghien cuu nay ciia tic gia nham kilm dinh sy tdn tai ciia hipu iing phi myln cua thu nhap dan tham nhung d cac qudc gia dang chuyen ddi bang viec sir dyng ky thuit phan tich hoi quy vdi du lieu bing nhim xac djnh dp Idn ciia cac hp sd mpt cich dang tin cgy.
2. Tong quan 1^ thuyet moi quan h§ giira thu nhap v^ tham nhung
Cic md hinh Iy thuySt ve nguyen nhan cua tham nhiing thudng xoay quanh van dl ve mdi quan he dai dien giiia gidi cdng chiic va xa hdi (Becker &
Stigler, 1974; Klitgaard, 1988). Ban cgnh do, mirc dp ciia hanh vi tham nhung ciing thudng dugc xem xet gan vdi mdi quan he ciia chat lugng the che cung nhu miic do phit trien kinh ta ciia qudc gia dd. Ket qua nghien ciiu cua Treisman (2000) va Graeff &
Mehlkop (2003) cho thay tham nhung chiu su tic ddng nghjch ciia mite dp phat tnan kinh ta, do dd cic qudc gia cd thu nhgp binh quan dau ngudi cao dugc cam nhan la it tham nhung hon cac qudc gia cd thu nhap binh quan diu ngudi thap. Tuy nhien, nghien cim cua Saha & Gounder (2013) sii dung dii heu cua cic qudc gia phan theo thu nhgp \a theo vimg de dinh gia cic yeu td tie ddng dan tham nhiing. Ket qui thyc nghiem cho thay mdi quan he cimg chieu giira thu nhip va tham nhung d cac qudc gia cd thu nhap thap, trong khi d cic qudc gia cd thu nhgp trung binh vi cao, sy tang len trong thu nhgp se lam giam tham nhiing.
Dudi gdc dp kinh te hpc vi md, sy khac biet trong thu nhip giua cac qudc gia tie dgng khdng gidng nhau den chi phi cua tham nhiing va qua dd nd ciing lam cho miic dg tham nhung khac nhau. Vi vay, viec
lam giau cua khu vyc tu thdng qua cac giao djch phi phap phy thudc vio chi phi va lgi ich ma hg nhan dugc tu hoat ddng tham nhung. Gidi cdng chiic ciing se suy doan chi phi ciia viec nhan hdi Id (chi phi \ e mat dao diic, xa hdi, kinh te) vdi lgi ich mong dgi cua hg. Ket qui cua su suy doan niy cd the phy thudc vao he thdng chinh tri, phap ly va su phat trien kinh ta cua qudc gia. Nghien ciiu ciia Becker (1974) cho thay miic Iuong cao ban cua cdng chiic se lam tang chi phi ciia viec nhgn hdi Id (giim tham nhiing).
Dua theo quan diam cho rang thu nhgp cao ciia cdng chiic se Iam tang chi phi ca hdi ciia hoat ddng tham nhiing, nghia la qudc gia ngheo dugc ky vpng la tham nhiing nhieu hon so vdi cac qudc gia giau, nghien ciiu cua Sandholtz & Koetzle (2000) chi ra rang do gii trj bian ciia thu nhgp d cic qudc gia ngheo la ldn nen thu nhgp tang them se anh hudng dang ke den chi phi cua c i ngudi dua va nhgn hdi Id. Ngudi dua hdi Id se dugc lgi khi ma khoan diit Idt nay tao ra co hdi cho hg hudng led nhieu han.
Tuang ty, ngudi nhan hdi Id cam thay xiing dang cho nil ro cua viec nhgn hdi Id khi ma gia trj thu dugc la ldn han so vdi tiln luang chinh thiic cua hp.
Kit qua nghien ciiu Leys (1965) cho thay tiln luong cua cdng chiic d cac qudc gia ngheo khdng dip iing nhu cau cudc sdng cho nen cac khoan dut Idt ciia khu vyc tu trd nen rat hap dan ddi vdi hg.
Mat khac, cac nghian cim tranh Iuan vl gia thuylt tham nhiing gay can trd hay thiic day tang trudng kinh te ciing cho ra cac ket qua trai chilu. Cic nghien ciiu irng hp quan diem tham nhung la "chat bdi tron" xem tham nhung nhu la thilt bj tilt kiem trd ngai da thuc day dau tu va tang tnidng kinh t l gdm cd Samuel (1968), Lui (1986), Beck & Maher (1986) va Lien (1990). Cac nghien ciiu nay cho ring d cac qudc gia cd thu nhgp thip se khdng tao ra du thu nhap de diit ldt cho cac gidi chiic. Nhung khi thu nhgp tang len ngudi dan cd du kha nang dl hdi Id cho gidi chiic vi vgy se lam miic do tham nhung trd nen tram trpng han. Do dd, cac nghien ciiu niy kit luan mirc dp tham nhiing cd the tang trong giai dogn dau ciia nen kinh ta chuyen ddi.
Tir thao Iuan tren cho thiy cic nan kinh tl chuyen ddi (qudc gia cd thu nhap thap) khdng tgo ra dii thu nhip da thyc hien tham nhung nham tim kilm co hgi gia tang lgi ich ciia khu vyc tu nhan. Tuy nhien, budc vio giai dogn dau cua thdi ky chuyin ddi, thu nhgp ngudi dan tang len da tao dilu kien cho hoat
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ddng tham nhung ngay cang trd nen nghiem trgng ban khi ma ci ben dua va nhan tham nhung deu cd dugc Igi ich hi hogt ddng nay ldn han chi phi ca hpi ciia nd. Nhung dilu nay se khdng the dugc duy tri khi sy phat triln cua nin kinh ta di vao cac giai doan tang trudng dn dinh (thu nhgp cao) vi khi dd chi phi cua tham nhung trd nen qua ldn. Dieu nay cho thay khi nang tdn tgi mdi quan he phi myen giua thu nhap va tham nhiing tai cic nin kinh tl chuyen ddi.
Ben canh thu nhap thi khung thi chl cung la mdt trong nhung ylu td dugc nghien ciiu nhieu ve sy tic ddng din tham nhiing Viec giam tham nhiing phy thudc rit ldn vao viec thiet ka khung tha cha ciia mot qudc gia, nd dugc xem la yau td cd the chdng tham nhung mpt each hieu qui. Saha & Gounder (2013) va Heckelman & Powell (2010) cho ring khung the chl bao gdm the che chinh tri va tha che kinh te Trong dd, the cha chinh trj dugc dgi dien bang nin dan chu cua qudc gia va the che kinh ta dugc dai dien bang ty do kinh te. Cic tic gii nay da sir dyng bien ty do kinh te (Economic Freedom) ciia EFW (the economic freedom of the world) dgi dipn cho tha che kinh te vi ket qui cho thiy muc do ty do kmh ta tic dgng lim giam tham nhung cho tat ca cac tnrdng hop Koteraetal (2012)vdidir lieu tren 82 qudc gia trong giai dogn tir nam 1995 dan 2008, sir dyng phuang phap udc lugng OLS da cung cd mdi quan he giiia quy md chinh phu vi tham nhiing dudi sy tic dgng ciia nen dan chii. Ong cho rang d cac qudc gia ma mirc dg dan chu vira du, sy tang quy mo chinh phu se giam tham nhiing bdi \i chinh phii dugc bd nhipm bang viec bau cu tu do vi hgp phap hogc tir quyet djnh ciia sd ddng cdng chiing. Trai lai, d cac qudc gia mirc dp dan chu qui thap, ca cau chinh phu khdng hogt dpng tdt, va kit qui li quy md chinh phii ldn lim cho tham nhiing nhieu hon. Qua do, tic gii ket luin rang de tan dung vai trd can thipp cua chinh phu mi khdng Iam tang tham nhiing, sy phat huy dan chii la rat can thilt, vi sy tien bd ciia nin dan chii se Iam qua trinh kiam tra vi can bang hoat dgng tdt, tir dd, mgt sy gia tang trong quy md chinh phu se din tdi sy giam di mirc dg tham nhiing. Kit qui nay phii hgp vdi nghien ciiu ciia Montinola & Jackman (2002) va Kotera et al. (2012).
3. Phirong phap udc lu^ng va dw lipu nghien ciru Muc tieu cua nghien ciiu nay li khim phi mdi quan hp phi tuyin giua thu nhap va tham nhung. Vi vgy, tic gia tiln hanh kiam dinh hai mo hinh ciia phuang trinh myln tinh va phuang trinh bac hai ciia
biln thu nhap. Md hinh myen tinh dugc dy bio co ® tdn tgi mdi quan h6 tieu cue giiia thu nhgp va tham nhiing. Md hinh phi tuyen gia thuylt ring tiln trinh phit trian kinh ta d cic qudc gia chuyen ddi se iam tang tham nhijng trong giai dogn dau nhung tham nhung se giim d giai doan phat trien dn djnh sau do, Ngoai ra, sy virng chae ciia khung thi che tien tiln cung giup ban chl va bay trir nan tham nhiing d ci^^i qudc gia.
3.1. Mo hinh vd dO-Ii^u
Md hinh nghiSn cuu dgi dien cho mdi quan hp phi myln giua thu nhap v i tham nhung dugc dya h^n bii nghian ciiu ciia Treisman (2000), Saha &
Gounder (2013) va Kotera et al. (2012). Tic gii tiln hanh phin tich dya tren mdi quan he tuyan tinh cl dian bang vipc sir dung cic bian dgi dipn cho nen kinh te xa hdi (thu nhap binh quan dau ngudi, chi tieu chinh phu, ty le that nghiep vi ty le hgc sinh dau vao bgc tiau hpc) vi cic bian dai dien cho khung the chl (nin dan chii vi tu do kinh tl). Mo hinh tuyen tinh cd dgng:
corit Po I- p,gdppc„ + pjgovsize,, f P3unemployment|,+ p^schoolenrollj, + pjeconomicfiee-g + Pddemoit + e^, (1)
Trong dd i va t la chi sd ve qudc gia vi thdi gian, Bian phy thudc cor la chi sd ve tham nhung dugc do ludng bang chi sd cim nhan tham nhiing (CPl) va dugc thu thap tir ngudn cua Td chiic Minh bach Qudc te (Transparency International). Bdi vi vipc do ludng mirc do tham nhung thyc la rat khd cho nen hiu het cac nghian ciiu thuc nghiem deu sii dung chi sd cam nhan tham nhiing - CPl da thay the cho miic dp tham nhung. Chi sd nay dugc do ludng theo diem tir 0 dan 10, theo dd qudc gia nao cd dilm cing nho cing it tham nhiing va ngugc lai. Vi vgy, khi dua vao md hinh thyc nghiem tac gia dieu chinh Iai sao cho gia tri cing ldn cing it tham nhiing bing each lay 10 trir di diem ciia CPl. Biln gdppc la thu nhap binh quan diu ngudi v i dugc liy tir WDI. Trong mo hinh myen tinh, he sd pj la dugc quan tam nhat va ky vgng dau cua pj la mang dau am. Govsize li quy md chinh phii dugc dai dien bang chi tieu diing cuoi cung ciia chinh phii va dugc liy tir WDI. Ve ly thuyat, chi tieu chinh phii cang tang cing tao dilu kien cho cdng chiic true lgi (tham nhiing), do dd p, dugc ky vgng mang dau duang (Kotera et al., 2012).
Ngugc Iai, hp sd P3 cua biln ty le thit nghipp dupc ky vgng mang diu duang do ty le thit nghiSp d cac qudc gia cd nen kinh te chuyan ddi thudng d mus:
So 222 Iking 12/2015
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cao (Kristiansen & RamH, 2006).
Ngugc lgi, ty le dan sd cd trinh dp hpc van se giiip hg de dang nhan ra quyin Igi, trich nhiem va nghia vu cua minh trong mdt qudc gia. Vi vay dan sd cd trinh do hpc van cang cao cang it chap nhan cac trudng hgp tham nhiing cua gidi chitc. Ky vgng dau cua P^ la am (Ali & Isse, 2002). Bien demo la nin dan chii dugc xay dung bing cich lay tnmg binh ciia chi sd quyin chinh tri va ty do dan chu dugc cung cap bdi td chiic Freedom House. Bien niy Cling dugc ma hda lai sao cho gii trj cang ldn la cing dan chii (liy 10 trir di gii tri tmng binh cua quyen chmh tri va tu do dan c hit) Mpt quoc gia dan chu se thuc day ca che giam sat ciing nhu sy ty do ngon luan ciia bio gidi va dieu nay se diy lui ngn tham nhiing mpt each hieu qua. Vl vay, he so Pj cung dugc ky vpng mang dau am (Kotera et al,, 2012). Ben canh dd, cac qudc gia mudn gia tang nang lyc canh tranh ciia mirdi de thu hut dau tu trong va ngoai nudc thi chi sd ty do kinh ta se dugc cai thien. Chi sd nay dugc xay dyng dya tran 37 tiau chi danh gia va dugc cau thanh 5 thanh phan' Quy md cua chinh phii; cau tnic phip ly va quyan sd hiiu; su lanh manh cua tien tp; su ty do giao dich vdi ngudi nudc ngoai; va, quy djnh ve tin dung, Iao ddng va kinh doanh. Vi vay cac qudc gia cd chi sd ty do kinh te cang cao dugc ky vpng cang giam tham nhung, nghTa la Pg dugc ky vpng mang diu am (Ades & Di Telia, 1999),
Sau dd, md hinh myen tinh dugc md rdng de khao sat su tdn tgi cua hipu iing phi tuyen giiia thu nhgp vi tham nhung bang each them vio md hinh bien gdppc2, Khi do, phuang trinh (1) trd thinh-
corit = ttp + ttigdppc,! + a2(gdppc,,)^ + a3govsizeit + a^unemployment^j + ajschoolenrolljj + ageconomicfreeu + a,demOj, + &„ (2)
Trong phuang trinh (2), hieu img phi tuyin cua thu nhap duac the hien thdng qua he sd hdi quy a, va Oj. Hieu iing phi myln tdn tai khi ma diu ky vong ciia aj la duong vi 03 la am^. Diu ky vpng ciia a^ va a, thi hien mdi quan he parabol (chii U ngugc) giua thu nhap vi tham nhiing. Tren dudng parabol nay se tdn tai mdt gia tri xic dinh ciia fhu nhap Iam cho tac ddng ciia nd len tham nhiing bang 0. Gii tri xac djnh niy dugc xem la ngudng cua thu nhgp trong hipu iing phi myln phuang trinh (2). Do dd. thu nhap tnrdc gia trj ngudng se tic dgng duang Ien tham nhung v i tic ddng am sau gii trj ngudng.
NghTa la, trong giai dogn diu thdi ky chuyen ddi.
mdt sy gia tang trong thu nhap se lim tang tham nhiing va se tiep tyc tang cho den khi dat miic cyc dai (miic ngudng). Nhung sau do, khi nen kinh te budc vao giai dogn phit trien dn djnh, su tang len trong thu nhap se Iam giam tham nhiing,
3.2. Phuffng phdp le&c lirffng
Trong nghian ciiu nay, tic gia su dung du lieu thu dugc cua 46 qudc gia cd nen kinh te chuyen ddi trong giai doan 2002- 2012 (dii Heu bing can bang).
Trudc het, de khao sat su tac dgng cua cac yau td chua dua vao md hinh la tac dpng cd dinh hay tac dpng ngau nhien, tac gia su dyng kiem djnh Hausman va ket qua cho thay hieu iing cd dinh giai thich tdt han cho md hinh thuc nghiem. Do dd, nghian ciiu nay sir dung md hinh hieu iing cd dinh (FEM) de udc Iugng do Idn he sd cic bien giii thich trong md hinh tuyen tinh va md hinh phi tuyen.
Ngoai ra, Moulton (1986) va Moulton (1990) cho rang khi sir dyng dii lieu bang de phan tich giiia cic qudc gia cd the gap phii su hien dien cua hieu iing nhdm dan tdi van de sai sd trong cac ket luan thdng ke. Vi vay, tic gia sir dyng phuang phip udc lugng binh phuang tdi thieu tdng quit (generalized least square) de xir ly hien tugng ty tuang quan cua cac quan sit trong pham vi qudc gia va phuang sai thay ddi giiia cic qudc gia. Cudi cimg, nhu tic gia da de cap, md hinh co the xay ra hien tugng ndi sinh do mdi quan he tuong hd giua tham nhiing va thu nhap, vi do dd tic gii su dung phuang phap 2SLS (two stage least square) hdi quy vdi bien cdng cu de kiem tra tinh viing cua cac udc lugng (Mauro, 1995; Saha
& Gounder, 2013).
Ket qui thong ke md ta cac bian trong mau khao sit cho thay gia trj trung binh chi sd tham nhiing d cic qudc gia cd nen kinh ta chuyan ddi la 7,2/10.
Chi sd nay cho thay miic dp tham nhiing d cac qudc gia nay la tuang ddi cao, trong dd co mdt sd qudc gia miic tham nhiing len tdi 8 4 chang hgn Cambo- dia, Chad, Burundi... Tuy nhien, trong cac qudc gia khao sat thi ciing cd mot sd qudc gia ty le tham nhiing thap hon miic tmng binh cua to chiic Minh bgch Qudc ta gdm cd Georgia va Rwanda d muc 4,7 va4,8
Thu nhap binh quan tran dau ngudi cua cac quoc gia khio sit cd miic dp chenh lech khi ldn, qudc gia cd thu nhgp cao nhat len den 3.891 USD trong khi do qudc gia cd thu nhap thip nhat chi cd 108 USD.
Cic qudc gia cd thu nhap cao trong mlu gom cd Ukraine, Indonesia, El Slavado. Gia tri tmng binh
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Bang 1: Thong ke rao tS cac biln trong mo hinh Bien
schoolenrollment economic freedom democracy gov size unemployment
Quan s^t 506 506 506 506 506 506 506
Trung binh 7.279 1.138,433 103373 6.348 5,926 13.509 7,600
D$ lech c h u i n 0,589 901,22 17,902 0,663 1,322 5,878 6,314
Nho n h i t 4,7 108,014 41,048 4,53 3,5 3,460 0,6
Liin nhat 8,4 3.891,038 149,951 7,73 8,5 39,645 38,7 Ngudn: Tinh lodn cda tdc gia
cua gdppc cho thay cic qudc gia khao sat cd thu nhap d miic tmng binh thip theo tieu chuan cua World Bank.
Cudi ciing, gii tri trung binh cua chi sd ty do kinh tl li 6,3/10 va ty do dan chu la 5,9/10. Gia tri nay cho thiy chit lugng khung the cha d cic qudc gia cd nin kinh tl chuyan ddi d muc trung binh kha. Tuy vgy, van cd mgt sd qudc gia cd chit lugng tha che rit thip khi ma gii tri nhd nhit cua chi sd nay chi d miic 4,5 va 3,5.
4. Thao luan kit qua thue nghiem Kilm djnh quan he nhan qua Granger D I xac dinh moi quan he nhan qua hai chilu giira hai biln thu nhap va tham nhiing, bii vilt sit dung md hinh kilm djnh nhan qui Granger. Y nghia cua mdi quan he dugc xac lap thdng qua miic y nghia ciia kilm djnh Wald (kilm djnh F) va cic he sd hdi quy.
Bang 2 thi hien mdi quan hp nhan qua hai chieu giiia biln cor, gdppc vi gdppc2. Ket qua cho thay giira cic biln diu tdn tgi mdi quan hp hai chieu vdi miic y nghTa 1%. Dilu nay cho thay tham nhung chju sy tic dpng nghjch chilu tir thu nhgp va nguoc lai thu nhip cung bj giam khi tham nhiing tang ian.
Moi quan he myen tinh
Bii vilt sir dyng kilm djnh Hausman (1978) de lya chpn giira md hinh hieu iing cd djnh va hieu ling nglu nhien cua cic ylu td khdng quan sat dugc.
Thyc chit, kilm dinh Hausman li xem xet cd tdn tgi sy tuong quan giiia thinh phan sai sd vi cic bian giii thich hay khdng. NIU kiam dinh Hausman cho mpt kit qui cd y nghta thi md hinh FEM phu hpp ban so vdi md hinh REM. Ket qui cot 1 va cot 2 cho thiy xic suit bic bd gii thuylt HO vdi miic y nghTa 5%, nghTa li cac thinh phan sai sd cd tuang quan vdi biln giai thich. Do dd md hinh FEM la thich hgp dl phan tich cho nghien ciiu nay.
Trudc tian, tic gia tap tmng phan tich mdi quan h? myln tinh giua thu nhap va tham nhiing d cic qudc gia cd nen kinh te chuyen ddi cua phuang trinh (1). Kat qui udc Iugng he sd hdi quy cua phuang trinh tuyen tinh dugc trinh bay d cdt (1) ciia Bang 3.
Tuy nhien, khi thyc hien kiem djnh phuang sai thay ddi giiia cac dan vj cheo vi tu tucmg quan giiia cac quan sat trong cung dan vj cho thiy md hinh hipu ling cd dinh xay ra cic hien tugng nay. Vi vay, tic gia su dyng phuang phap GLS da udc lupng phuong trinh (1) va kat qua the hien d cgt (3).
He so hdi quy cua biln gdppc mang dau am vi co y nghia thdng ke d mite 1%. Kit qua nay hd trg cho Bang 2: Kiem dinh quan hf nhan qui Granger
Bien phu thu$c Bien dpe l^p H | so hoi quy cor
cor gdppc gdppc"2
gdppc gdppc'2 cor cor
- 0 , 0 5 0 2 » "
-0,0086"«
- 2 , 5 3 2 0 " * -15,4130»"
1,007»»»
0,9356«»«
5 , 1 0 4 1 " * 2I,9384«»«
0 , 0 0 0 0 " » 0,0000»«*
0 , 0 0 0 0 « "
0,0000»»»
Ghi chit: *** bieu thj cho mirc y nghia 1%.
Nguon: Tinh loan cUa tac gia
Si 222 Ihing 12/201! 66
KUI^ilialli'len
Bang 3: Moi quan h^ giua thu nhap va tham nhung BieD
g#pc gdppc^2 democracy economic freedom unemployment schooloirollmen t govsize constant R2 Hausman (p-value) Wald test (p-value) D avidson-Mac K in n on (p-vahie) Sargan-Hansen (p-value) Quan sat Quoc gta
(1) FEM -0,0430***
0,0151 -0,2406***
-0,0143 0,0217 -0,0208 1,1575***
0,1600 0,0188
506 46
(2) FEM 0,1480"
-0,03 2 0 ' "
0,0186 -0,2519***
-0,0206 -0.0084 -0,0227 0,9498'**
0,1748 0,0335
506 46
(3) GLS -0,0133***
-0,0917***
-0,1245***
0,0093**
-0,0009 -0,0629"*
1.1359***
0,0000
506 46
(4) GLS 0,1054*
-0,0231*
-0,0480***
-0,0303 0,0151**
-0,0016 -0.0334"*
0,8446***
0,0000
506 46
(5) 2SLS -0,0637***
0,0122 -0,1858***
-0.0294*
0,0492 -0,0203 1.1320"*
0,1454
0,0000 0,0231 0,5540 506 46
2SLS (6) 4,5979***
-0,8128***
0,0698 -0,2129 -0,3598***
-0,3455 -0,0439
^,4037***
0,1487
0,0000 0,0370 0,3120 506 46 Ghi chu: *. **, *** bieu thi cho micey nghia 10%, 5% vd 1%.
Nguon: Tinh todn cua tdc gid
gia thuyat kinh te qudc gia tang ian se Iam giam tham nhiing, do dd thu nhap tang Ien ciing kiem ham miic do tham nhiing. Sd lieu thuc te cho thay trong giai doan khio sat mpt sd qudc gia cd thu nhgp tang Ien rit nhanh va tinh trgng tham nhung giim xudng dang ka. Ghana la minh chimg dien hinh cho ket qui niy. Thu nhap binh quan d Ghana vao nam 2002 chi d muc 312 USD trong khi dd chi sd tham nhung li 6,1. Nhung den nam 2012, thu nhap binh quan ciia qudc gia niy tang ian 1.646 USD vi chi sd tham nhiing giam xudng chi cdn 5,5. Tuong ty, thu nhip binh quan d An Dp trong giai dogn nghien ciiu tang gin 210% (tir 486 USD ian 1.503 USD) va chi sl tham nhiing giam tir 7,3 xudng cdn 6,4.
Nen dan chu va ty do kinh ta phan inh vai trd cua Idhung the che trong viec kiem soit tham nhiing. He sd hdi quy cua bien ty do kinh te mang dau am d tat ca cac cdt cua Bang 3 cho thay miic dp tham nhiing se giam khi ty do kinh te ngay cang dugc cii thien da hudng den nen kinh te thdng thoang vi minh bach. Kdt qua nay cung phu hgp vdi cac nghien cihi trudc day ciia (Saha & Gounder, 2013; Saha & cdng sy, 2009), Emerson (2006) va Sandholtz & Koetzle (2000). Tuy nhien, ket qua thyc nghiem cho thay su tic dpng cua bien democracy la khdng virng. He sd hdi quy ciia bien nen dan chii (democracy) lgi khdng y nghia thong ke vi mang diu duong d cdt (1) (2) vi (5) nhimg lai cd y nghTa thdng ke v i mang dau
am d cdt (3) va (4), nghia li khi nan dan chu dugc md rdng se giim dugc ngn tham nhung. 6 cac qudc gia cd nen kinh te chuyen ddi, khi ma chat lugng the che dugc cii thien se giup lam giim tham nhiing ding ke. Ngudi dan dugc sdng trong dieu kien ty do ngdn lugn, che dd biu cu cdng bing va ty do, mdi trudng kinh doanh thong thoing va minh bach se giup tao ra mot ca cha giim sat va chdng tham nhung cd hieu qua (Mauro, 1995).
He sd hdi quy cua bien govsize cho thay khi chinh phu gia tang chi tieu cdng se giup giam tham nhiing. Ket qui nay cung phu hgp vdi nghian cim ciia Kotera & cdng su (2012). Dilu nay cho thiy mdt qudc gia cd quy md chinh phu Idn han se thuc day mgt he thdng kiem tra, can bang va tang cudng trich nhiem tir dd giam bdt dugc tham nhung.
Cudi cimg, he sd hdi quy ciia bien unemployment va bien schoolenrollment deu khdng cd y nghTa thdng ka. Tuy nhien, kat qua udc Iugng GLS cho thay khi that nghiep tang se lam tang tham nhiing.
Kat qua niy cung phii hgp vdi ky vpng va trimg vdi ket qua thuc nghiem ciia (Saha & Gounder, 2013).
Mdi quan he phi tuyan
Ket qui udc luang cua md hinh FEM (cdt 2) ghi nhgn sy tdn tai cua mdi quan hp phi tuyen giira thu nhip binh quan va tham nhiing dudi dgng hinh chii U ngugc. Ly thuyat hinh chii U ngugc ngy y miic dp tham nhung ting len trong giai dogn dau nhimg sau
So 222 thing 12/2015 67
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dd giam khi thu nhap binh quan diu ngudi d cic quoc gia tang len. He sd hdi quy ciia bien gdppc mang diu duang, biln gdppc binh phuang mang dau im va diu cd y nghTa thong ke trong md hinh FEM va GLS (cot 2 va cot 4) cho thiy ton tai hieu iing phi myln giiia thu nhap vi tham nhiing. Ket qua nay ciing phli hop vdi kit qua thuc nghiem ciia Saha &
Gounder (2013). Dilu nay cho bilt tham nhiing tang trong giai dogn thu nhap binh quan thap va giam khi thu nhap binh quan d cic qudc gia chuyen ddi tang len. Kit qua thyc nghiem mpt lan nua khang djnh ly thuylt vl hieu iing phi myln giiia thu nhap va tham nhiing la that su tdn tai (Dzhumashev, 2014).
Kiem tra tinh virng
D I kilm tra md hinh cd bj npi sinh vi that sy can diing 2SLS, tic gii dua vao de xuat cua Davidson &
MacKinnon (1993) cho dii lieu bing. Kilm dmh Davidson & MacKiimon vdi gia thuylt HO md hinh khdng xay ra hien tugng ngi sinh. Kit qua kilm dmh (cot 5 vi 6) cho thiy gia trj p-value bing 0,0231 vi 0,0370 nan ta bac bd gia thilt HO (miic y nghTa 5%), nghTa la md hinh cd xiy ra hien tugng npi sinh. Vi vay, sii dung phuang phip 2SLS vdi cic bian cdng cu la phii hop.
Treisman (2000) va Gallup et al. (1999) cho ring khoang each dia ly ciia qudc gia vdi dudng xich dao cd tuong quan vdi miic dp phit trian kinh te (dugc do ludng bang thu nhap) do van de khi hgu va benh tat, trong khi dd khoang each dia ly khong mong quan den tinh trang tham nhung ciia qudc gia. Do dd, khoing each dja ly dugc sir dung lim bien cdng cu la phil hgp. Bien nay dugc thu thap dua tren ket qui tinh toan ciia La Porta et al. (1999). Ben cgnh dd, Sachs & Warner (1997) ciing cho rang moi thp tmng binh phan inh tinh trang siic khde cpng ddng.
Trong khi dd, tudi thp trung binh mong quan chat che vdi miic dp phat trien kinh te qudc gia (thu nhap binh quan) nhung ty le niy khdng anh hudng din miic dg tham nhiing cua quoc gia. Bian nay dugc thu thap tir WDI. Vi vay, nghien ciiu su dung biln khoang each vdi dudng xich dao cua cac qudc gia vi biln tudi thp tmng binh lam cong cy cho biln thu nhgp da xir ly hien tugng ngi sinh bing phuang phap 2SLS.
Tinh hgp li cua cac bien cdng cu sir dung trong phuang phap 2SLS dugc dinh gia thdng qua thing ke Sargan - Hansen. Kiem dinh Sargan - Hansen xic djnh tinh chat phu hgp cua bian cdng cu diing trong md hinh. Day la kiem dinh gidi han ndi sinh cua md So 222 thing 12/2015
hinh (overidentifying restrictions) vdi gii thuyet HO biln cdng cu la bian ngoai sinh, nghTa la khdng mong quan vdi sai sd cua md hinh. Vi the, gia trj Sargan cang ldn cang tot. Kiem djnh Sargan-Hansen cho thiy cic biln cdng cy dy bio tdt cho bien thu nhap trong md hinh (p-value bang 0,5540 va 0,3120).
Kit qui udc luang 2SLS tai cot (5) khang djnh Igi vai trd cua thu nhap trong viec kiem soat tham nhiing trong md hinh tuyin tinh la that su cd y nghia. Vi cot (6) Cling cho thiy mdi quan he phi myen giiia thu nhap va tham nhiing la viing. Ket qua phan tich tinh viing cua udc Iugng cung cap bing chiing mgnh me ring thu nhap tang len se giiip giim tham nhiing tgi cac qudc gia co nen kinh te chuyan ddi.
5. Kit luan va ham y chmh sach 5.1. Ket lugn
Vdi myc tieu nghien ciiu sy tdn tai mdi quan h?
phi tuyin giiia thu nhap va miic do tham nhiing, t^c gii tiln hanh phan tich hdi quy sy tie dgng ciia thu nhap binh quan dau ngudi cung vdi khung the che va yau t l kinh te xa hdi din tham nhiing cua 46 quic gia chuyin ddi trong giai doan 2002-2012. Phit hien thu vi cua nghian ciiu nay la tdn tai hinh chii U ngugc giiia thu nhap va tham nhiing. Phit hien nay khic vdi cac nghien ciiu trudc day. Cac nghien ciiu tmdc day cho thay mdi quan he myen tinh nghich giiia thu nhap va tham nhiing, nghia la cii thien thu nhap se giiip hgn chl tham nhiing mdt cich tich cue.
Tuy nhien, ket qua thyc nghiem cho thay giai doan dau cua su phit trian, thu nhgp ngudi dan tang len Iai thiic day hogt ddng tham nhiing nhieu ban tgi cac quoc gia chuyen ddi. Sau do, khi nin kinh te di vao giai doan phit trian dn dinh thu nhap tang len lam giam tham nhiing ding ke.
5.2. Gaiy chinh sdch
Dya vao kat qua thyc nghipm, tac gia de xuit mpt sd giii phap gdp phan kiem soit v i han che tinh trang tham nhung tai cac qudc gia cd nen kinh te chuyen ddi nhu sau:
Thli nhat, cai thien thu nhap cua gidi cong chiic nen dugc xem l i giai phap uu tien hing diu. Trong mau khao sit cho thay ty la tham nhung ludn d miic cao tgi cac qudc gia cd thu nhgp thip. (3 cic quic gia nhu Bumndi, Chad, Guinea vi Tajikistan, thu nhap binh quan chi d miic dudi 300 USD nhung chi sd tham nhiing la rat cao (tir 7,7 trd ian). Kit qua hli quy da cho thiy thu nhap giiip ban chl tinh trang
Kinh leilial Irien
68
tham nhung mdt each cd y nghTa thdng ke. Nhu vay, ben canh viec day manh cac giai phip de thiic day tang tmdng kinh tl, viec uu tian ngan sach thyc hien chinh sach cai cich luang trong khu vuc cdng se l i giii phip thiet thyc trong viec chdng tham nhiing.
Vi suy cho cimg, nan tham nhiing xuat phat tit thu nhap thap trong khu vuc cdng, va rihat la khi tien luong khu vuc cdng cdn thip han so vdi thu nhap khu vuc tu thi van nan tham nhiing se cdn tiep tuc tai dien.
Thli hai, cic qudc gia ciing nen xac dinh muc tieu trpng tam cho chiln luoc chdng tham nhiing nhung vin dam bao phat tnin kinh te dd la can thiet lap mdt thi chl kinh t l thdng thoing va minh bach.
Thiet nghT chinh phu cac qudc gia nen timg budc hoin thipn 37 tiau chi ciia bio cao thudng nien the gldl. Khi chi sl tu do kinh te dugc cii thien ddng nghTa vdi viec mpt qudc gia cd dip iing dugc tieu chi ve he thdng phap lugt va quyen sd hiiu, xay dung dugc ddng tien laiih maiih, tha hien sy ty do thuong mgi qudc ta va cac quy dinh ro rang se giiip thu hut dau m, tgo vipc lam cho nan kinh te. Tir dd, thu nhgp cua ngudi dan va gidi chiic tang len se
giam thieu dugc tinh trang tham nhiing.
Cudi Cling, khi nen kinh t l d cic qudc gia budc vao giai doan dau cua thdi ky chuyen ddi, tham nhiing cd xu hudng gia tang do khu vyc tu cd xu hudng diit lot nham tim kiem ca hgi kinh doanh cho minh. Khi dd, mgt qudc gia dugc thiet lap vdi khung the che chinh tn hudng din vipc md rdng nen din chu se giiip ngan chan va loai trir tham lihiing hieu qua hon. Dan chu d day khdng chi l i bau cii tu do va cdng bang ma con la van da ty do bio chi, tu do ngdn lugn. Dilu nay cho phep gidi tmyen thdng cd nhieu co hgi han dl cdng khai, len an nhiing sai sdt cua cac gidi chiec nham ki lugt va ngan chan sy tii dien ve sau. Dau biet ring viae cai cich mdt he thdng chinh tn nhim mang Igi mdt nin dan chu toin dien han khdng phii la dilu dl dang va nhanh chdng, nhimg ro rang la nd rit cin thiet va cip bich trong viec giam thiau va bai trii van nan tham lihiing. Tac gia cho rang dieu nay die biet quan trpng ddi vdi cac nudc dang trong giai doan chuyan ddi vi Ioai bd tham nhiing khdng chi la da duy tri dao diic xa hdi ma cdn md ra nhilu ca hdi phit trien dat nudc. n
Chii thich:
1. Cac nghien cmi bao gim (Saha & Gounder, 2013), (Bardhan, 1997); (Mauro, 1995); (Mo, 2001) 2. Dya theo kinh tl luong ciia Wooldridge (2012); Arellano (2003)
3. Xem Wooldndge (2012) ve udc luong phi tuyen va dau ky vong cua he so trong moi quan he parabol Tai lifu tham khao
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Thdng tin tac gia:
*Dgng Van Cu&ng, Thgc sy
- Td chuc tdc gid cong tdc: Khoa Tdi chinh Cong, Truang Dai hgc Kinh te Thdnh pho Ho Chi Minh - Linh vgc nghien ciru. Tdi chinh cong; Chinh sdch cong
- .Moi so Tgp chi da ddng tdi cong irinh nghien cuu • Tgp chi Phan lich vd Dif bdo. Tgp chi Cong ngh? Ngdn hdng. Tgp chi Phdt trien Hgi nhdp.
- Dja chl mail: dangcuong(a,ueh.edu.vn
