CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '9151119aacbb408b',cH: 'BN2d4J3FWlkgtiYJ2gocv0yCY.fqhXzscOSEE9a0zhQ-1740081478-1.2.1.1-Y1xGkvbbXdxmrH3I10Jm9B3m66RW3I42vmgwivyintEjQeyghUzZ6702VsfunPdL',cUPMDTk: "\/search?q=causal%20modeling&__cf_chl_tk=gLEeMu7unfx_JO8ZhWW3jkhxsvpjsYKeNRv.Wm31ji4-1740081478-1.0.1.1-Dezr9LzcRSNQiPsT0L4oQoLf2zJsSh7JavobFqZ_GVI",cFPWv: 'b',cITimeS: '1740081478',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "unsupported-browser",fa: "\/search?q=causal%20modeling&__cf_chl_f_tk=gLEeMu7unfx_JO8ZhWW3jkhxsvpjsYKeNRv.Wm31ji4-1740081478-1.0.1.1-Dezr9LzcRSNQiPsT0L4oQoLf2zJsSh7JavobFqZ_GVI",md: "OtZsppcf4dwzDLtoBxQJ1jrhesZx_3YeIpqIIuIpYHs-1740081478-1.2.1.1-sMA9zh.4of7umrpi9yRC8sVAs3RhTkvBe9tDymfhUCeC95zgMxHjvcqw52fKE0ab4z4gf5BKpgkHbuONswy8saaIDuc3meIqhmgxoAscJMYWyBM2NCCQKKaR57REnZRMsROkUZWpYrjPzcrn.ut6DWZNrKvOHfPqw.H6Vae0iABVf1OasIMNK9DshY5giCp2XgFfMuAuTOrmbaZpsfh82a1gmXMBTvLPxfA7sOkBffBTiKNA2avXbXw8QIdsc_wT1.W2ZpmDOF0pIWBXg8acFk09hO0x331BhNkBXpTfECKaBlp8FE3AMq804CXEN1lY4phGhMtHomi6i8CGCj6LxEahgfdofEytfsuIoh7_wASF_9jT8_yiaERdiF_rTO4DS0R8BIkUabxin6Dx7h5Je1hWRRAMJFJs2MXGWT_GD1zXsVlEMOXVg216Jm3_kNAQgWtYSAKfeFW50PrIZu.GjGgjDNNLSNWDGnM8qC.HbctRnC.Cn_YEee._0jRq6XIkU.XBlbR2ZtoG4o9b8unquL88_v9Cok4EAlTL7Vqnk_0jUdiLWSzRdInkHMbhhDZcABEyKi41R3MYHHxVtXnMSX_RiQcZJhtrLLW9vkCc1DwfiXQx3w9iKqB0yDIasa.Y7FDwQ3ip8YmY6Z1BGlriajuCkJPebl1Hp0gMgg2vTu6zGv0t1WYkT0sI_P51WPSoM3CBBOpu504TPpwrQAEBi4cCN6QI4DfQ6BwGSca5x5EvqnvHK7VhrMC7kPW.QTTydyAJDsfKLaP3wRTp1nQuQPQCUOQ9_Fnpuxu4i7b37zm3c3dny2958T0V6gXcf2f1iOSMDCdZIVCjt_OPsVE3sBZT1RR77xEDmaxOH8T4M3KMbYAOTBzdn8Ow.vNI2pQWjYxDYtqLnsDGw2gN4h_nMIOscU0EOuvr2ScNMAaJuUKhvzxcEgEstlg4LAwG12mcoxGEZJyX4V93Vg8rRtypoHLraaWsCWgOkIZvCUcgoIwG2MtyiM0Ml5fB8xkLhB34awb8yWyJdQMkNPxOMFoK1wIuixGnKB0duDwi1gn9yJdcR8La34WdgH.vT0_upR80xNpdIvwqMuTLhXCfnegl2kU6e7HNdkhyvY1kRKjPS6PLCdeGKV6AsEyPwoNW0Awh8ePdPNg.ccguF2C9wIerly8fZ8gxstzPUMrgOJG0VdU_Goa8VrApJfOyRYuEsGhxf2NoBg0xIoX77Dy1Q2B7aXQoB6Mv_kMfvANK1MtwBXbpf5i4HeAfzGvRjl5uG_pg1bo1fjxFGPg6Guy.tuz0X_zN7p0bM9ODUslTN1WEFPVnAF6lN5goPqfrUA11i4tLnBZpqNHG91Zty7IKzauZu4YkFK3OB3HklvO11E7lTX_KX22a5qAG85jrBV5_Hv611ELT4ApepugrWif7pZzhE93YZlI3FbRbChZn0ev3th9oAAnhGjg629GoJnRarakDEC_9BxZt07vifnFG5AhL2d3rwtB6YrmnYvRbcuIVVYcp7RdyFACogg.X0DUaGRK1KCxGkf_k1EnGilbDtF.PcLjIZL_fpZuEECivex_merFxCMRh9pHvMW6ybOSg7PPyIRFmSGDaGBbCawz8snu1ie56FNBjg2Jqnss0pf1al7bXVxjEklG47LIDjyaKojH7KpHsJqwu6Va8IT_GQqvSRjweKz._bRG3_RPgolYKA4Ca.EebwAlT_tFSO.YXFXLYdVlBAanOuA0BL7k0IeBAdMc24Prz1gUznxrUarIndpYquz9zl9TNeP05XfFuAgxaB0kuOmW6Vl0yuhy2RpRSCIcnrTw_jFyYGdqSN.dum9riGyZ4LKjFwTD5drrriOYpP3e6ta0fbOS9gUueCQYKGO5ooEuZS7bCIuklIT0aDbFlLtaMyW1LECHiUSnoeudFDlzFDbqYsX7xjKAg78uObQ",mdrd: "F8CKFFS8r2jPk.Tv4dlwAv_U36zt2FucEDTXv_tmJvU-1740081478-1.2.1.1-tlz_VEH8B70gcsVjlyPlyecfxPi5ynDLCq6GEyfxxTX3vxtNIng2cSwFZZV4UJ2JD7S2rA6QBZC.wQtAuj.btC9Zt5iFdX20NbPTagvAMqLqqZPudkWeKTXXpcXIYdWpEa9VvmJrkF5q.9YhyBJch57y4T6qx3GgztuFxkTlnQj7Dai9cZApVRxmS0UoQRemBEmXmuKqos_MlDDc5LjaxifqJOCUlCziwu0re7Z0YjJGggsPE4r9YTLz4ZAyJ._GxLFhUBSwfWajXVZqAqCHyszK87qy6lbjbWO5cwaxMl_xrc80hF.NcZPWFWf0.VKmvWFMkdtiJLHjXY.eq.ZJ6DR.6JnNtCZf93B9kMJEDs.xb1GwwRCugnO4QIqidV3GWowqm4v9YEVyeY1j1LeBSMMwDVPIj.fsnFkpXLeykKhbEk3PinLZOBhg.Np6ohNaiE0XEi0JrDpbqss954hcZVRSkwshGBvOld3b6j4Xb1784GKPrVMUB9xKBEIO8hspS1dtI4rrolrGfoPSNg1qlzUhhRR4JrjrAVd.TmaXazxDu..ilfkeS5rU529VydfUj0P6rTkmTDpQbyI3HBJQ6KEM.FZ0o6Iwyuv2RMparybTJ9GHgcyO64maJRIWfetxuxh7T8.uhTlo7dsM2l8Jfb0xYLsc35QlzE1cunwX.JhoU3gqt3DSHwuQZwy_eLDylv8wnxnQETJUp_laU2qfIkwYLtoG.YQA9XrM_0r6Gkm3_fkNH8M3LRvZypPXddEpVcvZpyrxiAPZXBuzFo7B7G5A6FQPW5i7iabDBB3AY3NIybFEEI98PU40NEl3NQ3XRmQ6RYOrNGuXWBc37qrP4b.aVILHAwMKVrGCZf5tt.Z_XV9rlmLCvwHpN18uVpcBaKZinLZtcH5MLVI9eHoKtdNNe7Y3JitGLdt6VmJznGVDcBO5krT_hu8rVWCtL0m3rSxJYmQT7KPtnvdYD5HXAa6Uv03OFD1EGuWEXMBY2ZcAQCKowmzbpjz3ztvdWY7Ene8gLb4rBGRsptrbkhjRB9Es5MKege8sfF5JFNkmK1JmjWyva70L8mIsyP6WRT2MhW1czoWp5aZJS8NhHi7pXYBadOGxt6difG0BefLXdm880STRJ9kjA8TueRN7kD_bPx8ju7_V_mmuaMbFELgQ720VR9WQ7bQ3Tw2Jq9eHrDGbhhJJTv7JSpyrcVwGKioQ8oafGbnKVS4RwfOUd.MJ2R4GmaSSDXS2neYFu2VBl9b7h19Tw3S4td6pl44qvE8GfmeKbyPcuoaYlkC8XvxT4YqTljGfDm8CzxVw87NJ96XiqwOJ4GqI9fQch2Tv4qM_COX_xVw7UvmxoKSpurhATNPVHU7ReGDmLSa3_noW3KjNDjRAIn9ElCdhaRjnH2hRtaqI3GI_5lZNX5EZ2o3rWsurkl4V.xSEwASua_uUWGVTNDrlKpyZsvjkuR4Ymvj4LdvR_9zJw1rEqM9C3K2GyVs.OHPIN0lEOX_PPKB9FNNue3kfR0OOr7Ntj82nRT.O.hns3_a.EAjz8NsRzTyWzi0G4kKnJ.7tK_zCwXkzFEMbS3zhnxw1A79giELHU1.FkBE_0ay6fHyK9CPcac1O6vWIPqRPoEE8YhMCziNpV62sDh5dqDcAB.spQRZFOh6k08C470ZRJS02M9GW29nE_tNDXiX5g71og0tsCX1vSC9yQ97oBh8CTBQz_4wHAhmr_Grpg_pS7E.UnMxKYlfJY1Nps182mm8H4BGP24Xv6EqLyB1UrroxdOOeTwf.L1typM0.qV3BUa0MYPF7J4CEkFMsEeJCgAA6ByqBgR_K7Wt8ht5ZGq3gV_L6FtWwIHtKjfF9o3mnexx.PM0iCpblWE4qYSCJZ8Vt5j2VoiT3GZ.rrW.VZS067upg_voJ5q0.Crk5WQjuhmWRoBO2fLmaSDwrExDoJAjsc3LLLYKV676Y3N4kzAjqlwAdH_hVaqlf"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9151119aacbb408b';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/search?q=causal%20modeling&__cf_chl_rt_tk=gLEeMu7unfx_JO8ZhWW3jkhxsvpjsYKeNRv.Wm31ji4-1740081478-1.0.1.1-Dezr9LzcRSNQiPsT0L4oQoLf2zJsSh7JavobFqZ_GVI" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>