Lý thuyết tăng trưởng PGS TS đàm xuân hiệp

PGS. TS. DAM XUAN HIEP Lt rrnuykr TANG TRIJONG iii NHA XUAT BAN KHOA HOC VA 1(1 7 THU lAT HA NOI - 2010 Lol N61 Mill Tang tru6ng luOn la chii de ciia nhieu cuOc tranh luan khac nhau gida nhieu nha kinh to hoc, giira nhieu tm6ng phai hoc thuyet khac nhau. DO cling la van de dapc nhieu nha nghien cdu cling nhu thkrc hanh chinh sach vi me quan tam. Tim du'oc ban chat citing clan cna tang truCing co the gitip Ich cho cac nha hoach dinh va ra guy& dinh chInh sach kinh to cua mot qu6c gia. Cu6n sach nay dua ra mot gOc nhin ye ban chat dm tang tru6ng. Thoat dau, cuon sach dupe bien soar' nham phuc vu mot phan cho cac bai giang trong mOn chuyen de to chpn "1/ thuyet kinh to dOng" ma tac gia thtic hien tai mot so khod cao hoc nganh Quan tri Kinh doanh cua truerng Dai hoc Bach Khoa Ha NOi. Tuy nhien, tai lieu cling co the duorc dimg de phuc vu hoc tap cho sinh vien va cac can 1D0 nghien cau cua cac chuyen nganh khac lien quan den kinh to hoc vi mo nhu: kinh to cOng nghiep, kinh to nang lacing._ CuOn sach bao g6m nhang not dung co ban nhu sau: Chuang I: Tang trua'ng can bang. Chuang 2: Nguyen ttic yang caa tang trtang vci van de' phan chic thu nhap. Chuang 3: Phdn tich them ve ccich nhin tan co Chuang 4: Tang tniong phi can bang. Chuang 5: Tang truang nOi sinh va tang truang ngoai sinh. Chuang 6: Cac mo hitzh phi can bang. Chuang 7: Ccic !no hinh can bang. 3 Day la Ian xuat ban dau tien nen có the cuein sach khOng tranh dugc thieu sot v6 not dung lan hInh thdc trInh bay. Chung tOi rat mong nhan dtroc cac y kien &rig gop cUa dpc gia de nang cao chat luong cu6n sach trong Lan tai ban tiep theo. Noi tie'p nhan cac Y kien: Nha xuat ban Khoa hoc va Ky thuat - 70 Tran Hung Dao - Ha NQi; hoac dia chi email: hiepdx(&epu.edu.vn . Tran trong cam on! Tdc gid TANG TRUING CAN BANG Trong thuyet "can bdng tang guar cUa Keynes, Ong da gia thiet rang lacing dkr trfr tu ban khOng d6i va dpc lap vOi dau to trong 14. Trong mO hinh "khd Wang tang tradng can bdng", Keynes cling da dua vao hai nhan t6  "cung" dau tu (tang truOng kha nang san xugt tuong lai) va su tac Ong taping 116 dPng gifta "cung" va "cau" (tac Ong cUa he s6 tang t6c). Dim vao hai nhan t6 co ban nay, Keynes da xay dung cac hoc thuyet hien dai ye tang truOng kinh to va cac hoc thuyet ye chu trinh. Nhieu tac gia sau nay ding dd dung cac gia thiet cUa Keynes de nghien cdu qua trinh phat tridn ho4c tang truOng. Gang nhu vay, lan dau tien vao nam 1936, nha kinh to hoc Kalecki Et de cap den nhung khai niem co ban ye hoc thuyet chu trinh dip trC, 'n hai nhan to "cung" va "cau". Sau do, nha kinh to hoc Samuelson ti6p tuc nghien cau van de nay. Tiep theo, hai nha kinh to hoc not tieng Harrod va Domar da phat tridn hoc thuyet nay IT* cach town dien va hoan chinh. Nhieu nha kinh to da g9i chung day la mO hinh "Harrod - Domar". MO hinh nay da dua ra mot 56 dac tinh cling nhu cac diet' kien cho qua trinh tang truOng can bang. 1.1. BAN CHAT "KEP" COA DAU TU . Mpt nen kinh to luOn luOn chiu tac dpng dong thei cUa cling va cau tir qua trinh dau tu, va to goi nom na la "tac dOng kep". Qua nhan t6 "cau" (s6 nhan), dau to xac Binh duoc tang thu nhap va tang cau; con qua nhan t6 "cling", dau tu ding lam tang truOng nang ivy san xufft. 5 Cau Xac dinh eau (s6 nhan) Tang cau Al OQ ~ = Tang nang ltrc san xuat AQ s = / Nha kinh to hoc Domar da dua ra cau hoi nhu sau: trong dieu kien nao thi tang cau se tuung thich voi mac tang tra6ng nang luc san xuat do qua trinh dau tu dem Iai? Neu ta gia thiet he s6 tu ban khOng d6i, voi mac tang tru6ng nang lkrc san xuat tY le thuan voi mac dau tu va ta c6 Wong dau tu r6ng, theo dinh nghia, bang mire bien thien A lacing du trir to ban thi ne'n kinh to se xuat hien dau hieu cua sir tang truemg. Ben canh clueing cau, dau tu cung xac dinh auk thu nhap thOng qua s6 nhan Keynes. Mat khac, tang tru6ng cau phu thuOc vao mac bien thien trong dau tu. Ta c6 the tham khao hinh 1.1 sau day: Dau ttr ren2 I Cung Tang tradt g tu ban AK =1 Can bang A/ s — = — /  v Hinh /./. Hai tac nhan ctia dau tu • D6i voi duong cung: d6 la tong dciu tu cho phep xac dinh mac dO tang truOng (/). • D6i vai duong cau: do la mac tang tru&ng dfiu to Al. 6 Do vay, neu ngay hOm nay ta dau tu mot khoan lien nham dieu chinh cau theo nang luc san xuat thi ngay mai ta can phai dau tu nhieu hem n[ra b6i vi chi c6 dau tu moi thuc su lam tang nang luc san xuat (Domar). De duy tri mitt can bang giila tang cung va tang cau, ta can phai thus su quan tarn den dau tu. Do vay, muc dau tu can tinh town hop ILT de lucrng ta ban va sCrc san xuat se tang tru6ng ved mot tSf le khOng d6i va bang t37 ' s6 gitla lai suat tiet kiem so v6i he se; tu ban. Do vay, khi ta c6 mot khoan dau ta reng thi dieu do c6 nghia la nang luc san xuat se tang truOng; can bang gida du6ng cung va dung cau chi la can bang  ta khOng the c6 can bang nao khac ngoai sit' tang tru'dng da du' c can bang, ding c6 nghia la khOng c6 can bang fia. Trong khi nha kinh to hoc Domar chi - mg minh tinh thiet yeti ye van de 1u9ng tu ban va sac san xuat phai tang trudng theo m0t tS , le khOng d6i thi ngagc lai, nha kinh to hoc Harrod lai chi ra rang, ban chat cna tang truOng kinh to la khOng on dinh. Tir lap luan nay, Harrod da dat ra hai cau h6i: • MOt la, tinh on dinh cua su tang twang can bang. • Hai la, kha nang duy tri mot xa hoi c6 day du tong an viec lam. 1.2. TINH PHI ON DINH CCM TANG TRIfoNG Bang viec dua ra khai niem ye tang trudng du kien trong qua trinh xac dinh lacing dau tu, nha kinh to hoc Harrod da rut ra ket luan: ban chat cUa mei quan he tru6c day xac dinh t57 le tang truOng so \Jai 6/ ' le gida lai suat ti& kiem va he s6 ta ban la khOng on dinh. Tuy nhien, tren thuc cac bai via dm Harrod van chug cung cap day di' cach chdrig minh ro rang ve tinh phi 6n dinh cna su tang trudng, them chi Harrod cling khOng neu duot nguyen nhan cita tinh phi 6n dinh nay. Van de mJ nay da du6c nhieu nha kinh to hoc quan tarn nghien cdu tiep va ho da chung minh dugc rang, v6 thuc chat, tinh phi on dinh Harrod cling chinh la tinh phi 6n dinh cUa he s6 tang tCic trong thuyet chu trinh: viec dieu chinh kip died he se dau tu se clan den ITHIC Bien d'Ong cua cau va attic Wen clOng cUa nang luc sari xuat khOng bie'n thien theo cung mot tri s6. 7 • Tang truerng cau d A/ 0, AQ = = 5 =5% s 10 Cluing to hay ding nhau xem xet van de thong qua so . d6 hinh 1.2. Gia thia rang he s6 tu ban bang 2% va lai suat tiet kiem rang bang 10%. Do vay, mdc tang twang can bang tuong img voi 5%. Tren du6ng tang truOng nay, mdc dau tu rang, mire tieu thu,  san xugt (hoac mcrc thu nhap) va lacing tu ban ding tang v6i tY le 5% (hinh 1.2a). Neu cac doanh nghiep quy& dinh dau tu dua tren tee dp tang trithrig du kien la 5% thi mtic tang truang cung va cau thuc su se dUng bang tY le tang trueng du kien va bang 5% (tY le tang traCing can bang nay dupe goi la tY le bao dam - Harrod). a) Tang throng dtr kien AO,* = 5% • Dau tu rang 1= 10% • Tang twang nang lkrc san xugt AQ" =- 2 / =5% b) Tang twang du kien z1Q*= 6% • Dan to rang 1 = 12% Tang throng ming luc san xual AQs2= 6% Tang twang cau A/ 2, AQ ` = = 5 = 25% S  10 Hinh 1.2. Tinh phi b6n vting Harrod a) Tang triang can bang ; b) Tinh phi ben yang. 8 Bay gio to gia thief rang cdc chu doanh nghiep do kien t6c de tang twang bang 6%. Nhu vay, de nang lot san xuat tang 6% thi tY le dau tu can phai tang fir 10% den 12%. Mat khdc, de tang 1% nang luc san xuat (L. - mg v6i Mat tang truong chung tit 5% den 6%) thi dau tu can phai tang 20%. Do tdc Ong ciia he s6 tang t6c, mac tang them dm eau xuat phat to ink tang them ciia dau to cling se bang 20% Nhu vay, mire tang truong cung tif 5% den 6%, con mac tang truong cau tit 5% den 25% (hinh 1.2b). Do (16, cac nha doanh nghiep se can phai tang dau tu de bit dap mac chenh Lech giCra cung va cau; nen kinh to hu6ng va dat t6i su bong n6 v6 toc dO tang truong. Nguqc lai, neu t6c de tang truong throe du kien thap hon 5% thl dieu nay clan den met &rang cau qua yeu kern, va nhu vay nen kinh to se phai dei mat v6i so suy thodi co the. Vi du nay da neu re nguyen nhan cua tinh phi 6n dinh: tdc Ong dm he s6 tang toc dau tu khOng clang met tri s6 vei tdc Ong dia he s6 nay len tee do tang truong cung (tic Ong dm he se tang t6c) ngoai tar dei voi met gia tri hang hod rieng biet king v6i the de tang truong can bang. Do do tdc deng cila he se tang t6c se qua cao bOi hai 17 do: thir nhat, mO hinh tang truong nay da be qua cdc nhan t6 ngoai sinh cua (long cau (cdc chi phi cung Ong, xuat khaki, dau to trong nuoc va dau tu thay the); thd hai, m6 hinh nay cung bO qua th6ng s6 thei han hieu chinh ma thOng s6 nay c6 tdc dung lam on dinh hod he s6 tang t6c. 1.3. TANG TRLONG KINH - ft VA VleC LAM Van de did hai ma nha kinh to hoc Harrod neu ra, do la so tic Ong qua lai gida tang truong kinh to va met xa 110i day du viec lam. Bang cdch dua ra nhirng lap Juan nguoc lai voi hoc thuyet "tY le tang truong bdo ddin"(tY le nay lam can biting cung va cau tren thi truing hang hod con tY le tang truong to nhien cho phep duy tri so can bang thi twang lao &Ong), thi met nghich ly xuat hi0: "so dOi lap gida hoc thuyet Keynes va hoc thuyet c6 diL". Neu tji le tang truong bao dam g„, cao hon t57 le tang truong to nhien, nen kinh to c6 the cho phep c6 met t6c de tang truong cao, vi du 9 nhu sau su suy thoai chung tram trong cUa mot nen kinh te", c6 the cho phep lam giam b6t nan that nghiep: g = g„,> g„  (1.1) Nhung khi nen kinh to huong tai viec tao day dU cOng an viec lam cho ngtred lao dpng thi t9 le tang tru6ng hien hau g se bi giai han b6i t9 le tang tru6ng to nhien. Khi do mac tang truOng thuc se tr6 nen thap hon t9 le tang tru6ng dam bao. Ta nhang nghien can nay, dPng tiled bang each nhan manh den tinh phi on dinh da dua ra tru6c day, Harrod rat ra ket luan: nen kinh to se dan dan bi suy thoai do sac cart qua yen. Ngoai ra, Harrod cling dua ra ket luan: lai suat tiet kiem qud cao hoac qua thap ding deu gay anh hung tieu cuc den cOng an viec lam cUa ngithi lao dpng. Tiet kiem se tr6 thanh nhan to tich cuc nen t9 le tang tru6ng bao dam thap hon t9 le tang truOng to nhien; nguoc lai tier kiem se tr6 thanh nhan t6 lam suy thodi nen kinh to nen luong tien do tiet kiem qua du thaa so voi kha nang tang trudng dan s6 va kha nang phat tridn cUa khoa hoc cOng nghe. 1.4. TANG TRUONG KINH TEVA THol GIAN TAI SAN XUAT TU . BAN Cac 19 luau truck day &roc torn lupc thOng qua viec xac Binh hai dai lacing lam co s6 cho mO hinh Harrod - Domar: do la 6 k tang triOng to nhic")n va 6 4' 3 tang triOng bao chin?. Ve mat 19 luan, chung 1a nhang yen t6 lam co so cho m6i lien he giCra tai san xuat to ban va qua trinh tang trueng kinh te. ThOng qua viec khai quit hod bang mot s6 nhan t6, nha kinh td hoc Leontieff da dua ra mot mO hinh clpng voi chat nang tao &roc nhieu viec lam trong nhang nam 1960. Nhung thu vi nhat van la each tiep can cUa nha kinh to hoc Von - Neumann vao cuoi nhUng nam 1930 voi tu9ng sat nhap hai nhan t6 to ban va lao dpng thanh nhan to c6 kha nang tai san xuat. Sau d6, nha kinh to hoc Brody da nghien cau phat tridn tiep 19 thuyet nay. 14 thuyet da  ra mot 16i giai thIch ttrong d6i hoan chinh v6 cac giai doan kink nhau cUa qua trinh tang tru6ng nen kinh to dua tren th6i gian tai san xuat cUa cac nhan t6 san xuat. Trong inO hinh da nhan to thupc clang Von - Neumann - Leontieff, tat ca cac nhan to deu c6 kha nang tai san xuat va ky thuat san xuat chi la 10 tdc nhan phu, tY le, tang trudng t6i da cUa nen kinh to duoc xac dinh theo Cy le &la lai suat tier kiem va he s6 tu ban duoc sir dung (nhu trong mO hinh Harrod met loaf hang hod). Khi mot loci hang hoa tit' ban du' dila) thi gia cna no bang khOng va loai hang hoa do se" /along toe dOng den m6i pan he _vac dinh 6 le tang trudng tOi da ci;a nen kinh te: Do vay, tdc d6 tang trudng kinh to se khdc nhau tuY thuec vao mac dau tu rong dugc gibi han chi theo lacing tich luy tu ban luu d6ng (v6n luu d6ng) hoac nguot lai, ddu tu rOng lien quan den tang tu ban c6 dinh (v6n co dinh) va tang von nhan luc (hinh 1.3). Gia thik rang lai suat tier kiem bang 10%. Trong th6i kY tai thik xay dung, v6n c6 dinh va luc luong lao deng ky thuat (nhang lao deng c6 trinh de cao) clang du thaa. De tang sac san xuat, ta can phai tich luy to ban luu deng - von hat dOng (tieu dUng trung gian). Neu lacing du tri to ban luu deng bang 0,5 Lin sac san xuat hang nam thi \Jai lai suat tik kiem 10% se cho ta mac tang trung kinh to bang 20%: 0 .1  = 20 % g v  0.5 (1.2) Hinh 1.3. Tang train - 1g va tai san xuat ttr ban Khi v6n c6 dinh khOng du thaa nua nhung ngu6n nhan lac van con du thaa (khi san xuat khUng hoang thaa, nen kinh to thu6ng dan den du thaa lao deng, ke ca lao deng có trinh de cao, fir cOng nghiep den nOng nghiep ), ddu tu rang se rot vao von co dinh (tu ban c6 dinh); nhu vay he se; to ban (v) se tang va c6 gia tri tit 1,5 den 2. Lai suat tik kiem rOng 10% se lam tY le tang trudng dao deng trong khoang ta 5 den 7,5%. T6c do tang trung tuong ang v6i thai kY "skr phdt tri6n dieu kS , cua nen kinh te'. Ne s n kinh te . thein k . 57da duoc biet den v6i cdc nu6c Chau Au va &it 11 [...]... mot cach nhin d6i lap voi nhang mO hinh co dieu chinh truoc day Kaldor gia thiet rang khuynh huong tiet kiem tien (khuynh hung tiet kiem to ban) s, cao hon khuynh huang tiet kiem nhan cOng s„, Do do, tS7 le tiet kiem se la mot ham tang tru6ng phan lqi nhu4n cl4t &roc to khOi luting san phtim trong nuot va t5, le tang tru'O'ng bao dam (sly) ciing trd thanh mot ham tang tweing t57 suat loi nhuf.in (hinh... cap, phan tich cdc nhan t6 tic Ong d6n sir tang trtrong trong kST dai 3.1 TICH LUY T61 T61 LIU XA HOI VA -r6i U'U NHAN Trong mO hinh tang traong tan c6 dien duqc phat trien vao giira nhirng nam 1950, tS le tiet kiem dupt gid thi6t la khOng d6i (sau nay, Harrod va Domar deu sit dung gia thi6t Keynes nay) VI vay, viec ltra chon tjT le tiet kiem bang bao nhieu la van de gay tranh cai gida cac ca nhan... giira t6i uu xa hOi va sir can bang c6 canh tranh Neu cdc 110 dan cu xdc dinh mire phan chia tieu thu - tiet kiem cua ho bang each t6i da hod lgi ich vat chat trong dieu kien han the v6 ngan quy7 thi tS, le sinh led ar tai ' san tai chinh cua cac 110 dan Cu nay (tY suat lqi Ich r) trong truemg hqp tang tru6ng can bang se bang tong hai dai luong: qi le tang tru6ng va t5/ suat uu dai hien tai: r=g+0... cdc deng gop cUa tirng nhan to, dugc xric dinh theo phan tra tin luting c6a tong nhan to san xuk • Neu to ky hieu a - phan Igi nhuan; (1 - a) - chi phi lao Ong; 27 g - ty le tang tru6ng san xuat; k - tS7 le tang tru6ng tu ban; ' n - tY le tang lao clpng; thi ta c6 m6i quan he sau: g= ak + (1-a) n + y (3.111 Thanh phan y bieu dien t6c dp phat trier' khoa hoc ky thuat, c6 nghia la su tang tru6ng nay... sir dung tat ca cac ngu6n ltrc ye may moc thie't 111 (16 nang suat lao dOng can phai cao hon auk Wong thuc phai tra (hinh 3.2a) Nang suat lao Ong bien bang s6 Wong thuc phai tra Ta ding nhan thay rang tS, suat 19i nhuan bang nang suat to ban rung bier' CuOi ding, v6i tinh hu6ng vd nen kinh to tang truCfng cho truoc, v* tang lai suat fief ki4n se lam tang s6 lacing san pham binh quan dau nguoi bang cach . to có mot lacing to ban/dau ngued qua dia) (diC,rn A - hinh 2.3), thi tY le tang truOng bdo ddm - c6 nghia la tY le tang truOng to ban - se cao hon tY le tang tru&ng sire lao &Ong. chia thu nhap. Khi luting to ban/ dau ngubi qua thap (diem A - hinh 2.1), thi sac san xuat bien to ban - c6 nghia la tY suet lgi nhuan - se cao hun tY suat loi nhuan ling v6i str tang tru6ng can. din : Ham san xuat v0 nang suat khOng dPi:  Q = F(K,N)  (2.1) trong do: Q - ham san xuat; K - v6n; N - lao (16ng. Bang each chia cho s6 lao Ong, ta xac dinh dupe m6i quan he giira