lanruoJ fo scirtemonocE 25 )2991( .95-5 dnalloH-htroN HCRA gniledom ni *ecnanif A weiver of eht yroeht dna laciripme ecnedive miT velsrelloB Northwestern ,ytiswrinU Er,anston, IL 60208, USA yaR Y. uohC Georgia Institute of Technoloa, Atlanta, GA 30332, USA htenneK .F renorK University of Arizona, Tucson, AZ 85721, USA hguohtlA ytilitalov gniretsulc sah a gnol yrotsih sa a tneilas laciripme ytiraluger gniziretcarahc ycneuqerf-hgih evitaluceps ,secirp ti saw ton litnu yltnecer taht deilppa srehcraeser ni ecnanif evah dezingocer eht ecnatropmi fo ylticilpxe gniledom gniyrav-emit redro-dnoces .stnemom latnemurtsnI ni tsom fo eseht laciripme seiduts sah neeb eht evissergerotuA lanoitidnoC yticitsadeksoreteH )HCRA( ledom decudortni yb elgnE .)2891( sihT repap sniatnoc na weivrevo fo emos fo eht stnempoleved ni eht noitalumrof fo HCRA sledom dna a yevrus fo eht suoremun laciripme snoitacilppa gnisu laicnanif .atad lareveS snoitseggus rof erutuf ,hcraeser gnidulcni eht noitatnemelpmi dna stset fo gnitepmoc tessa gnicirp ,seiroeht tekram erutcurtsorcim ,sledom noitamrofni noissimsnart ,smsinahcem cimanyd gnigdeh ,seigetarts dna eht gnicirp fo evitavired ,stessa era osla .dessucsid nA* reilrae noisrev fo siht repap yb T. ,velsrelloB .R ,uohC .N namarayaJ dna .K renorK saw :deltitne HCRA‘ gniledoM ni :ecnaniF A evitceleS weiveR fo eht yroehT dna laciripmE ,ecnedivE htiw snoitsegguS rof erutuF .’hcraeseR eW dluow ekil ot knaht ruo seugaelloc ohw depleh ylppus eht secnerefer detic ni siht .yevrus gnomA ynam ,srehto ew dluow yllaicepse ekil ot knaht zuB ,kcorB nhoJ ,llebpmaC yaR ,oranneGeD knarF ,dlobeiD boR ,elgnE nitraM ,snavE sakiG ivaR ,nahtannagaJ nanayaraN ,namarayaJ .J notsuH ,hcolluCcM moT ,ydruCcM naD ,nosleN nairdA .nagaP reteP ,nosniboR lliB ,trewhcS nehpetS ,rolyaT -icitrap stnap ta eht ecnerefnoC no lacitsitatS sledoM fo laicnaniF ytilitaloV ta DSCU no lirpA ,7-6 ,0991 dna na suomynona eerefer rof yrev lufpleh dna deliated stnemmoc no na reilrae .tfard miT ,velsrelloB yaR ,uohC dna neK renorK dluow ekil ot egdelwonkca laicnanif troppus morf FSN ,70822-09SES# eht aigroeG hceT ,noitadnuoF dna eht lraK rellE retneC ta eht ytisrevinU fo ,anozirA .ylevitcepser 000.50$/29/6704-4030 reiveslE-2991 ecneicS srehsilbuP .V.B llA sthgir devreser 6 T. Bollerslec et al., ARCH modeling in finance 1. noitcudortnI ytniatrecnU si lartnec ot hcum of nredom ecnanif .yroeht gnidroccA ot tsom asset gnicirp seiroeht the ksir muimerp si denimreted yb the ecnairavoc neewteb the erutuf nruter no the asset dna eno or erom kramhcneb -oftrop ;soil e.g., the tekram oiloftrop or the growth rate ni .noitpmusnoc nI noitpo gnicirp the ytniatrecnu detaicossa htiw the erutuf ecirp of the gniylrednu asset si the tsom tnatropmi tnanimreted ni the gnicirp .noitcnuf ehT -noc noitcurts of hedge soiloftrop si rehtona elpmaxe where the lanoitidnoc erutuf secnairav dna secnairavoc gnoma the tnereffid assets devlovni yalp na -ropmi tnat .elor elihW ti has neeb dezingocer for etiuq emos emit that the ytniatrecnu of evitaluceps ,secirp as derusaem yb the secnairav dna ,secnairavoc are -gnahc gni hguorht emit [see, e.g., torblednaM (1963) dna amaF (1965)1, ti was ton litnu yltnecer that deilppa researchers ni laicnanif dna yratenom scimonoce evah started ylticilpxe gniledom emit noitairav ni -dnoces or redro-rehgih .stnemom enO of the tsom tnenimorp sloot that has degreme for -ziretcarahc gni hcus gnignahc secnairav si the evissergerotuA lanoitidnoC -sadeksoreteH yticit )HCRA( ledom of elgnE (1982) dna sti suoirav .snoisnetxe ecniS the noitcudortni of the HCRA ledom lareves derdnuh research papers gniylppa siht gniledom ygetarts ot laicnanif emit seires data evah ydaerla appeared. nI siht paper we yevrus those snoitubirtnoc that we redisnoc ot eb the tsom tnatropmi dna gnisimorp ni the noitalumrof of epyt-HCRA sledom dna rieht snoitacilppa ni the gniledom of evitaluceps .secirp lareveS gnitseretni scipot ni laciripme ecnanif gnitiawa erutuf research are osla .dessucsid ehT nalp of siht paper si as .swollof eW nigeb ni noitces 2 htiw a feirb weivrevo of emos of the tnatropmi laciteroeht stnempoleved ni the -emarap noitaziret dna noitatnemelpmi of epyt-HCRA ,sledom dna eunitnoc ni -ces noit 3 htiw snoitacilppa of the HCRA ygolodohtem ot stock nruter data. snoitceS 4 dna 5 revoc the gniledom of tseretni rates dna ngierof egnahcxe rates, .ylevitcepser A deliated yhpargoilbib si nevig at the dne of the paper. 2. HCRA gniwolloF the lanimes paper yb elgnE (1982) we llahs refer ot lla etercsid emit citsahcots processes 1~~( of the mrof )1( ,E = ;OtZ 7 z, ,.d.i.i E( )lz = 0, (rav zr) = 1, htiw a, a ,gniyrav-emit ,evitisop dna elbarusaem noitcnuf of the emit t - 1 noitamrofni set, as na HCRA .ledom roF won E, si demussa ot eb a .T Bollersle~ et ,.la ARCH modeling in finance 7 etairavinu process, tub snoisnetxe ot etairavitlum sgnittes are drawrofthgiarts as dessucsid .woleb yB noitinifed E, si yllaires detalerrocnu htiw naem zero, tub the lanoitidnoc ecnairav of ~F slauqe ,2tu hcihw yam eb gnignahc hguorht .emit nI tsom snoitacilppa E, lliw dnopserroc ot the noitavonni ni the naem for emos other citsahcots process, yas ,},y{ where )b;,_,x(g=,y ,rs+ )3( dna g(x,_ ;, )b setoned a noitcnuf of x,_ 1 dna the retemarap rotcev b, where x,_ 1 si ni the emit t - 1 noitamrofni set. oT yfilpmis the ,noitisopxe ni tsom of the noissucsid woleb we llahs emussa that t& si flesti .elbavresbo Let f(z,) etoned the ytisned noitcnuf for z,, dna tel 0 eb the rotcev of lla the nwonknu sretemarap ni the .ledom yB the noitciderp error -isopmoced ,noit the doohilekil-gol noitcnuf for the elpmas Ed, e7._,, . . . , F, ,semoceb apart morf laitini ’,snoitidnoc L(6) = :i )&+gol[ - .],tUgol )4( l=t ehT dnoces mret ni the noitammus si a naibocaJ mret gnisira morf the noitamrofsnart morf z, ot .,F Note that (4) osla senifed the elpmas -ilekil-gol hood for ,7y _,y , , . . . , ,y as nevig yb (3). neviG a cirtemarap noitatneserper for f(z,), mumixam doohilekil setamitse for the sretemarap of tseretni nac eb detupmoc yltcerid morf (4) yb a rebmun of tnereffid laciremun noitazimitpo .seuqinhcet ehT putes ni eqs. (1) dna (2) si ylemertxe lareneg dna swolla for a ediw yteirav of .sledom tA the emas ,emit the cimonoce yroeht gninialpxe -opmet lar noitairav ni lanoitidnoc secnairav si yrev .detimil ,yltneuqesnoC ni the redniamer of siht noitces we llahs etartnecnoc no emos of the erom -sseccus luf emit seires seuqinhcet that evah neeb depoleved for gniledom at2. esehT sledom for the laropmet ecnedneped ni lanoitidnoc sdnoces stnemom raeb hcum ecnalbmeser ot the emit seires seuqinhcet for lanoitidnoc tsrif stnemom deziralupop ni the ylrae .seitneves tsuJ as the noitargetni of emit seires seuqinhcet for the lanoitidnoc naem otni larutcurts cirtemonoce ledom gnidliub has del ot a hcum deeper dna rehcir gnidnatsrednu of the gniylrednu ,scimanyd ralimis stluser evah ydaerla started ot egreme ni the gniledom of lanoitidnoc secnairav dna .secnairavoc ‘Throughout this ,repap the ecnedneped of E( dna ,a on the retemarap rotcev 6 era desserppus for notational .ecneinevnoc 8 T. Bollerslec et al., ARCH modeling in finance 2.1. The linear ARCH(q) model sA elgnE (1982) stseggus ni sih lanimes paper, eno elbissop -aziretemarap noit for at2 si ot express 2tu as a raenil noitcnuf of past derauqs seulav of the process, 4 ta +w=2 ,:E)L(a+w=i_:&,a~ i=l where w > 0 dna ~Y( 2 0, dna L setoned the gal operator. sihT ledom si nwonk as the raenil )q(HCRA .ledom htiW laicnanif data ti serutpac the ycnednet for ytilitalov ,gniretsulc ,.e.i for egral )llams( ecirp segnahc ot eb dewollof yb other egral )llams( ecirp ,segnahc tub of elbatciderpnu .ngis nI order ot ecuder the rebmun of sretemarap dna erusne a cinotonom gninilced effect of erom tnatsid shocks, na ad hoc ylraenil gninilced gal erutcurts was netfo desopmi ni ynam of the reilrae snoitacilppa of the ;ledom ,.e.i ~Y( = a(q + 1 - i)/(q(q + 1)) as ni elgnE (1982, 1983). roF z, yllamron ,detubirtsid the lanoitidnoc ytisned gniretne the doohilekil noitcnuf ni (4) takes the mrof gol f(8tVf1) = - 0.5 rr2gol - ?,U2,&5.0 (6) mumixaM doohilekil (ML) desab ecnerefni serudecorp for the HCRA ssalc of sledom rednu siht lanoitubirtsid noitpmussa are dessucsid ni elgnE (1982) dna alutnaP (1985). hguohtlA the doohilekil noitcnuf si ylhgih raenilnon ni the ,sretemarap a elpmis gnirocs mhtirogla si elbaliava for the raenil )q(HCRA ledom denifed ni (5). ,eromrehtruF a egnargaL reilpitluM (LM) test for (Y, = .. . =a4 = 0 nac eb detaluclac as TR* morf the noisserger of &f no ,,-:F . . , ,~-:E where T setoned the elpmas .ezis sihT emas test si yllareneg dilav gnisu yltnetsisnoc detamitse slaudiser morf the ledom nevig ni (3). nA evitanretla tub yllacitotpmysa tnelaviuqe gnitset erudecorp si ot tcejbus :& ot dradnats tests for laires noitalerroc desab no the -alerrocotua noit ,erutcurts gnidulcni lanoitnevnoc uaetnamtrop tests as ni gnujL dna xoB (1978). nI ,noitidda yrogerG (1989) stseggus a cirtemarapnon test for )q(HCRA devired morf a etinif state vokraM niahc ,noitamixorppa elihw nosniboR (1991) stneserp na LM test for yrev lareneg yllaires tnedneped .yticitsadeksoreteh ehT llams elpmas ecnamrofrep of emos of these -amitse tors dna test scitsitats evah neeb dezylana yb ,elgnE ,yrdneH dna elbmurT (1985), dlobeiD dna yluaP (1989), velsrelloB dna egdirdlooW (19911, dna yrogerG (1989). ,ylgnitseretnI the nwonk-llew llams elpmas drawnwod saib for the retemarap setamitse ni evissergerotua sledom for the naem seirrac revo ot the setamitse for (Y,, . . . , qa *.osla tI‘ si osla htrow gniton taht ni eht ecneserp fo )q(HCRA ,stceffe dradnats stset rof laires noitalerroc ni eht naem lliw dael ot ;snoitcejerrevo ees ssieW ,)4891( rolyaT ,)4891( johliM ,)5891( dlobeiD ,)7891( dna ztiwomoD dna oikkaH )7891( rof rehtruf .noissucsid T. Bollerslec et al., ARCH modeling in finance 9 sA na evitanretla ot ML ,noitamitse epyt-HCRA sledom nac osla eb detamitse yltcerid htiw dezilareneG Method of stnemoM .)MMG( sihT was detseggus dna detnemelpmi yb Mark (1988) ahtrudoB dna Mark (1991) ,netsolG ,nahtannagaJ dna elknuR (1991), nomiS (1989) dna ,hciR ,dnomyaR dna reltuB (1990a, ,)b dna ni a ylesolc detaler txetnoc yb yevraH (1989) dna nosreF (1989). A nosirapmoc of the ycneiciffe of exact ML, isauQ mumixaM doohilekiL (QML), dna MMG setamitse gnisu tnereffid tnemurtsni sets dluow eb .gnitseretni naiseyaB ecnerefni serudecorp nihtiw the HCRA ssalc of sledom are depoleved ni a seires of papers yb ekeweG (1988, 1989a, ,)b who sesu etnoM olraC sdohtem ot enimreted the exact roiretsop -ubirtsid .snoit nA yllanoitavresbo tnelaviuqe noitatneserper for the ledom ni ,)lc (2) dna (5) si nevig yb the gniyrav-emit retemarap )q(AM ,ledom 4 ,i-q;,z& &,=W,+ l=r where .,,,a,,~ . qta,. are .d.i.i htiw naem zero dna ecnairav w, (Y,, . . , ,qra .ylevitcepser sihT pihsnoitaler neewteb the gniyrav-emit retemarap ssalc of sledom dna the raenil )q(HCRA ledom has neeb rehtruf deiduts yb yasT (1987) Bera dna Lee (1989,1991), miK dna nosleN (1989) ffloW (1989) gnuehC dna yluaP (1990) dna Bera, ,sniggiH dna Lee (1991). ,ylralimiS ni ssieW )b6891( dna sniggiH dna Bera (1989a) snosirapmoc ot the raenilib emit seires ssalc of sledom are .deredisnoc 2.2. The linear GARCH(p, q) model nI ynam of the snoitacilppa htiw the raenil )q(HCRA ledom a gnol gal htgnel q si dellac for. nA evitanretla dna erom elbixelf gal erutcurts si netfo dedivorp yb the dezilareneG ,HCRA or ,p(HCRAG q), ledom ni velsrelloB (1986)” ;a;e:_,+ .2~u)L(B+:a)L(a+w=,‘~u;B~ ,a +w=2 )7( =i 1 l=i oT erusne a denifed-llew process lla the sretemarap ni the redro-etinifni RA noitatneserper a,* = :EM = (1 - :E)L(~‘-))L(P tsum eb ,evitagennon where ti si demussa that the roots of the laimonylop P(h) = 1 eil edistuo the tinu ;elcric see nosleN dna Cao (1991) dna Drost dna namjiN (1991). roF a )l,l(HCRAG process siht stnuoma ot gnirusne that htob iy~ dna p, are .evitagennon tI swollof osla that E, si ecnairavoc yranoitats fi dna ylno fi ehT3 elpmis GARCH(1, 1) ledom saw yltnednepedni detseggus yb rolyaT .)6891( 01 T. Bollersleue t al., ARCH modeling in finance )l(a + )l(p < 1.4 Of ,esruoc ni that noitautis the ,p(HCRAG q) ledom -erroc sdnops yltcaxe ot na redro-etinifni raenil HCRA ledom htiw yllacirtemoeg gninilced .sretemarap nA gnilaeppa erutaef of the ,p(HCRAG q) ledom snrecnoc the emit seires ecnedneped ni .:E gnignarraeR ,smret (7) si ylidaer deterpretni as na AMRA ledom for E,” htiw evissergerotua sretemarap c4L) + p(L), gnivom egareva sretemarap ,)L(p-- dna yllaires detalerrocnu noitavonni ecneuqes ”,E{ - .}:a gniwolloF velsrelloB (1988), siht aedi nac eb desu ni the noitacifitnedi of the orders p dna q, hguohtla ni tsom snoitacilppa p = q = 1 si dnuof ot 5.eciffus hcuM of nredom ecnanif yroeht si cast ni smret of suounitnoc emit citsahcots laitnereffid ,snoitauqe elihw yllautriv lla laicnanif emit seires are elbaliava at etercsid emit slavretni .ylno sihT tnerappa gap neewteb the yllaciripme detavitom HCRA sledom dna the gniylrednu cimonoce yroeht si the sucof of nosleN ,)b0991( who shows that the etercsid emit GARCH(1, 1) ledom segrevnoc ot a suounitnoc emit noisuffid ledom as the gnilpmas lavretni gets ylirartibra 6Llams gnolA ralimis ,senil nosleN (1992) shows that fi the eurt ledom si a noisuffid ledom htiw on ,spmuj neht the etercsid emit secnairav are yltnetsisnoc detamitse yb a dethgiew egareva of past slaudiser as ni the GARCH(1, 1) .noitalumrof rehtonA elbissop nosaer for the sseccus of the ,p(HCRAG q) sledom ni gnitamitse lanoitidnoc secnairav si dessucsid ni Brock, ,heisH dna noraBeL (1991). yehT show that fi :E si raenil ni the esnes of yeltseirP (1981), the ,p(HCRAG q) noitatneserper yam eb nees as a suoinomisrap noitamixorppa ot the ylbissop etinifni dloW noitatneserper for .:E elihW noitagergga ni lanoitnevnoc AMRA sledom for the lanoitidnoc naem si ,drawrofthgiarts laropmet noitagergga nihtiw the HCRA ssalc of sledom si ton .suoivbo ,revewoH ni na lufthgisni tnecer paper, Drost dna namjiN (1991) show that the ssalc of ,p(HCRAG q) sledom si desolc rednu laropmet ,noitagergga yletairporppa denifed ni smret of tseb raenil -cejorp .snoit ,oslA dlobeiD ,b6891( ,>S891 gnisu a dradnats lartnec timil meroeht epyt ,tnemugra shows ecnegrevnoc towards ytilamron of a elagnitram process htiw HCRA errors rednu laropmet .noitagergga 2.3. Nonnormal conditional densities tA the emas emit that ycneuqerf-hgih laicnanif data tibihxe ytilitalov ,gniretsulc ti si osla ylediw dezingocer that the lanoitidnocnu ecirp or nruter n14 na gnitseretni tnecer ,repap nesnaH )0991( sevired tneiciffus snoitidnoc rof raen hcope ecnedneped dna eht noitacilppa fo dradnats citotpmysa yroeht ni a GARCH(1, 1) .ledom sA5 detniop tuo ni johliM )0991( nihtiw eht txetnoc fo eht )l(HCRA ,ledom eht citotpmysa dradnats rorre rof eht snoitalerrocotua dna eht laitrap snoitalerrocotua rof e: sdeecxe /l if ni eht ecneserp fo ,HCRA suht gnidael ot yllaitnetop rewol rewop fo hcus .stset %ee osla eht nosirapmoc ni rolyaT )a0991( fo eht lacitsitats seitreporp fo eht GARCH(1, 1) dna evissergerotua modnar elbairav )VRA( sledom detavitom yb noisuffid .snoitalumrof T. BollersleLle t al., ARCH modeling in finance 11 snoitubirtsid dnet ot evah fatter sliat naht the lamron ;noitubirtsid for emos of the tseilrae ecnedive see torblednaM (1963) dna amaF (1965). hguohtlA the lanoitidnocnu noitubirtsid for E, ni the ,p(HCRAG >q ledom htiw -idnoc lanoit lamron errors as nevig yb ,)lc (2), (6), dna (7) evah fatter sliat naht the lamron noitubirtsid [see jlchliM (198.5) dna velsrelloB (1986)1, for ynam laicnanif emit seires ti does ton yletauqeda tnuocca for the .sisotrukotpel tahT ,si the dezidradnats slaudiser morf the detamitse ,sledom ,i = ,‘-tGflE netfo appear ot eb ’.citrukotpel gniwolloF etihW (1982), citotpmysa dradnats errors for the sretemarap ni the lanoitidnoc naem dna ecnairav snoitcnuf that are tsubor ot serutraped morf ytilamron evah neeb devired yb ssieW (1984, 1986a). velsrelloB dna egdirdlooW (1991) tneserp a tnetsisnoc rotamitse for siht tsubor -oc-ecnairav ecnairav xirtam ni na HCRA krowemarf that seriuqer ylno tsrif ,sevitavired together htiw na noitartsulli of the llams elpmas ecnamrofrep of the -amitse tor dna the seitreporp of the tsubor 'RT egnargaL reilpitluM tests ni egdirdlooW (1988,199O). tI si dnuof that the lanoitnevnoc dradnats errors desab no the retuo tcudorp of the tneidarg-isauq deniatbo rednu the -pmussa noit of lanoitidnoc ytilamron dnet ot etatsrednu the eurt dradnats errors for the sretemarap ni the lanoitidnoc ecnairav noitauqe nehw lanoitidnoc -pel sisotrukot si .tneserp esehT saedi are osla detartsulli yllaciripme ni eilliaB dna velsrelloB (1991).” elihW the QML desab ecnerefni serudecorp are drawrofthgiarts ot -elpmi ,tnem ylluf tneiciffe mumixam doohilekil setamitse yam eb preferred ni emos .snoitautis nI noitidda ot the laitnetop sniag ni ,ycneiciffe the exact mrof of the error noitubirtsid osla syalp na tnatropmi elor ni lareves tnatropmi snoitacilppa of the HCRA ,ledom hcus as noitpo gnicirp dna the noitcurtsnoc of lamitpo forecast error ;slavretni see elgnE dna afatsuM (1992) dna eilliaB dna velsrelloB (1992). velsrelloB (1987) stseggus gnisu the dezidradnats t-tnedutS noitubirtsid htiw the degrees of modeerf gnieb ”.detamitse Other cirtemarap seitisned that evah neeb deredisnoc ni the noitamitse of HCRA sledom edulcni the nossioP-lamron erutxim noitubirtsid ni noiroJ (1988), the power laitnenopxe noitubirtsid ni eilliaB dna velsrelloB (1989), the lamrongol-lamron erutxim noitubirtsid ni heisH (1989a), dna the dezilareneg laitnenopxe noitubirtsid ni nosleN .)~0991( nI a detaler ,txetnoc hcolluCcM (1985) stseggus the esu of na etinifni ecnairav citrukotpel elbats naiteraP tI‘ swollof morf s’nesneJ ytilauqeni taht htiw a yltcerroc deificeps lanoitidnoc .ecnairav eht ssecxe sisotruk ni ’~,u,E tonnac deecxe eht ssecxe sisotruk ni ;,E ees heisH .)a9891( tA‘ eht emas ,emit gnitcartsba morf yna ,ecnerefni nosleN )d0991( sah nwohs taht eht lamron doohilekil-isauq sesaercni htiw erom esicerp ytilitalov setamitse yletairporppa( ,)denifed elihw siht si ton yllareneg eurt rof lamronnon doohilekil .snoitcnuf nI“ eht suounitnoc emit yllanoitidnoc lamron ,ICHCRAG )1 noisuffid noitamixorppa dessucsid ni nosleN ,)b0991( eht snoitavonni devresbo revo trohs emit slavretni era yletamixorppa -birtsid-t .detu 21 ?i Bollerslec et al., ARCH modeling in finance noitubirtsid ni eht mumixam doohilekil noitamitse fo eht dellac-os evitpadA lanoitidnoC ,yticitsadeksoreteH ro ,HCA .ledom As an evitanretla ot mumixam ,doohilekil a cirtemarapimes ytisned -amitse noit euqinhcet dluoc eb desu ni gnitamixorppa .),t(f gniwolloF tnallaG and akhcyN ,17891( ni tnallaG and nehcuaT ,)9891( ,tnallaG ,heisH and nehcuaT ,19891( and ,tnallaG Rossi, and nehcuaT ,10991( ),z(f is decalper yb a laimonylop ,noisnapxe saerehw elgnE and areviR-zelaznoG )1991( suggest a ytisned rotamitse yllanigiro depoleved yb aipaT and nospmohT ”.18791( yB gnidiova yna cificeps lanoitubirtsid ,noitpmussa cirtemarapimes ytisned -itse noitam sevig an dedda ytilibixelf ni eht .noitacificeps fO ,esruoc derapmoc ot lluf noitamrofni mumixam doohilekil htiw a yltcerroc deificeps ,ytisned eht cirtemarapimes hcaorppa ylbairavni sevlovni a ssol ni citotpmysa .ycneiciffe ,revewoH htiw yldekram deweks snoitubirtsid eht ycneiciffe fo eht -arapimes cirtem rotamitse serapmoc ylbarovaf htiw eht LMQ setamitse deniatbo rednu eht noitpmussa fo lanoitidnoc ;ytilamron ees elgnE and areviR-zelaznoG .)1991( 2.4. Nonlinear and nonparametric ARCH nI eht ,p(HCRAG )q ledom )7( eht ecnairav ylno sdneped no eht -ingam edut and ton eht sign fo .*E As dessucsid ni noitces 3.3 ,woleb this is tahwemos at sddo htiw eht laciripme roivaheb fo kcots tekram secirp erehw egarevel stceffe yam eb .tneserp nI eht laitnenopxE ,)q,p(HCRAG ro ,p(HCRAGE ledom decudortni yb nosleN ,)cO991( a: is an cirtemmysa q), noitcnuf fo past S‘,E as denifed yb ,11( ,12( and ~a,(9z,i+r[lz,~,I ~P,lOg~~;. +o=Z,rcgol )]I,-,zIE- + i=l i=l )8( ekilnU eht raenil (HCRAG ledom ni ,)7( ereht era on snoitcirtser no eht p, q) sretemarap (Y~ and ip ot erusne ytivitagennon fo eht lanoitidnoc .secnairav ,suhT eht noitatneserper ni 18( selbmeser an detcirtsernu ARMA(p, q) ledom rof gol .2ru fI 4iyc < 0, eht ecnairav sdnet ot esir )llaf( nehw .Y_~ is evitagen )evitisop( ni ecnadrocca htiw eht laciripme ecnedive rof kcots snruter dessucsid .woleb Assuming ,z is .d.i.i ,lamron ti swollof that (E is ecnairavoc yranoitats dedivorp all eht stoor fo eht evissergerotua laimonylop )A(P = 1 eil edistuo eht tinu .elcric ehT HCRAGE ledom is ylesolc detaler ot ehT“‘ tcaf taht eht noitamrofni xirtam si ton kcolb lanogaid neewteb eht ytisned‘ ’sretemarap dna eht HCRA sretemarap setacilpmoc eht evitpada noitamitse fo eht HCRA ,sretemarap sa detseggus yb elgnE dna areviR-zelaznoG .)1991( T. Bollerslec et al., ARCH modeling in finance 13 the cimhtiragol noitaziretemarap dessucsid yb ekeweG (19861 dna alutnaP (1986) dna the evitacilpitluM HCRA ledom detseggus yb johliM ,b7891( c), gol 2,u = w + t ,a gol ;_“,z + 5 gol(;P i-T - gol .>& l=i l=i ynaM other evitanretla cirtemarap HCRA snoitalumrof evah neeb -disnoc ered ni the ,erutaretil gnidulcni power snoitamrofsnart of &f as ni the raenilnoN HCRA ledom of sniggiH dna Bera )b9891( dna Bera dna sniggiH (1991) dna a dlohserht HCRA ledom as ni naiokaZ ;10991( see osla elgnE dna velsrelloB (1986). nI the dlohserht ,ledom the at2 si a raenil esiweceip ,noitcnuf ybereht gniwolla tnereffid snoitcaer of ytilitalov ot tnereffid sngis dna sedutingam of the shocks. A detaler ,ledom desab no a vokraM niahc approach, si proposed yb xuoreiruoG dna trofnoM (1992). ,oslA ,yevraH ,ziuR dna anatneS (1992) evah yltnecer proposed na devresbonu stnenopmoc emit seires ledom ni hcihw HCRA secnabrutsid are decalp no htob the state dna gnitadpu .snoitauqe A erom lamrof nosirapmoc of these ynam evitanretla snoitalumrof dluow eb .evitamrofni daetsnI of gniyler no a cirtemarap noitatneserper for a,‘, a cirtemarapnon noitamitse euqinhcet dluoc eb desu ni gnitamixorppa the lanoitidnoc -irav .ecna gniwolloF nosniboR (1987a, ,)b lareves ,srohtua gnidulcni nagaP dna hallU (1988), nosniboR (19881, reltsihW (19881, nagaP dna gnoH (19901, dna anatneS dna inawhdaW (1989), evah detacovda lenrek sdohtem ni hcihw 2Ta si detamitse as a dethgiew egareva of ,:E t = 1,2,. . . , T, hcus that E,‘S for hcihw the gninoitidnoc set denifed( ni smret of deggal )noitamrofni ’esolc‘ ot that of 7& seviecer the tsehgih ”.thgiew lareveS tnereffid gnithgiew semehcs are ,elbissop tub the tsom tneuqerf ni the noitamitse of HCRA sledom evah neeb naissuaG .slenrek yreV elttil si nwonk tuoba the etinifni elpmas -reporp seit of these seuqinhcet ni the tneserp .txetnoc nA evitanretla cirtemarapnon noitamitse ygetarts sevlovni gnitamixorppa the nwonknu lanoitidnoc ecnairav noitcnuf yb a seires noisnapxe where the rebmun of smret ni the noisnapxe si na gnisaercni noitcnuf of the elpmas .ezis roF ,ecnatsni ni the elbixelF reiruoF mroF decudortni yb tnallaG (19811, gf2 si detamixorppa yb a noitcnuf of laimonylop dna cirtemonogirt smret ni deggal seulav of E,. nI the cirtemarapnonimes approach ni tnallaG dna akhcyN (1987) the cisab aedi si ot ylpitlum the lamron ytisned ni (6) yb a laimonylop .noisnapxe roF gnisaercni orders of siht ,noisnapxe rednu weak snoitidnoc the mumixam doohilekil setamitse dnuof gnisu siht dohtem evah the emas lacissalc seitreporp as cirtemarapnon .setamitse nI snoitacilppa of siht aedi redro-wol-yrev laimonylop snoitamixorppa evah yllacipyt neeb ;desu oT“ draug tsniaga eht ecneulfni fo ,sreiltuo eht ’tuo-eno-evael‘ rotamitse si netfo ;detpoda ,.e.i 7 # .t 14 T. Bollerslev et al., ARCH modeling in finance see, e.g., nagaP dna gnoH (1988), tnallaG dna nehcuaT (1989), dna ,tnallaG ,heisH dna nehcuaT (1989). A good noitartsulli dna nosirapmoc of emos of the tnereffid cirtemarap dna cirtemarapnon sdohtem dessucsid ni siht noitcesbus si nevig ni nagaP dna Schwert (1990). 2.5. ARCH-in-Mean models nI the ,naeM-ni-HCRA or ,M-HCRA ledom decudortni yb ,elgnE ,neiliL dna sniboR (19871, the lanoitidnoc naem si na ticilpxe noitcnuf of the lanoitidnoc ecnairav of the process, as nevig yb (11, (21, dna nI siht ,ledom na esaercni ni the lanoitidnoc ecnairav lliw eb detaicossa htiw na esaercni or a decrease ni the lanoitidnoc naem of ty gnidneped no the ngis of the laitrap evitavired of g(x,_,, ;‘(v b) htiw respect ot a,‘. ynaM seiroeht ni ecnanif evlovni na ticilpxe tradeoff neewteb the ksir dna the expected .nruter ehT M-HCRA ledom si yllaedi detius ot gnildnah hcus snoitseuq ni a emit seires txetnoc where the lanoitidnoc ecnairav yam eb .gniyrav-emit ehT tsom nommoc seciohc for the lanoitcnuf mrof of g(x,_ ,i ;*lo b) evah devlovni raenil or cimhtiragol snoitcnuf of at2 or cf. ,yllamroF noitamitse of the M-HCRA ledom poses on added .seitluciffid ,revewoH ni the ecnesba of M-HCRA effects, the noitamrofni xirtam -bo deniat rednu the yrailixua noitpmussa of lanoitidnoc ytilamron si kcolb lanogaid neewteb the sretemarap ni the lanoitidnoc naem dna ecnairav snoitcnuf of the .ledom sihT si on regnol eurt for the M-HCRA .ledom ,suhT ekilnu the raenil HCRAG ledom ni (7) where tnetsisnoc setamitse of the sretemarap ni the noitcnuf ;,_,x(g b) nac eb deniatbo neve ni the ecneserp of noitacificepssim ni a,‘, tnetsisnoc noitamitse ni the M-HCRA ledom seriuqer that the lluf ledom eb yltcerroc .deificeps sihT slellarap the stluser for cirtemmysa ecnairav snoitalumrof hcus as the HCRAGE ledom ni (8), where correct noitacificeps of the lluf ledom si yllareneg deriuqer ni order ot eetnaraug ;ycnetsisnoc see nagaP dna uabaS (1987a) dna nagaP dna gnoH (1990). citsongaiD tests for the ecnairav noitacificeps therefore emoceb yrev tnatropmi erofeb snoitaterpretni are edam tuoba the retemarap .setamitse ehT ycnetsisnoc tests deniltuo ni nagaP dna uabaS )b7891( mrof the sisab for eno hcus set of .scitsongaid 2.6. Persistence in variance A nommoc gnidnif ni hcum of the laciripme erutaretil gnisu ycneuqerf-hgih laicnanif data snrecnoc the tnerappa ecnetsisrep deilpmi yb the setamitse for
Description: