{"id":13522,"date":"2021-04-14T09:36:12","date_gmt":"2021-04-14T09:36:12","guid":{"rendered":"https:\/\/analystprep.com\/study-notes\/?p=13522"},"modified":"2026-05-27T18:34:19","modified_gmt":"2026-05-27T18:34:19","slug":"autoregressive-conditional-heteroskedasticity","status":"publish","type":"post","link":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/","title":{"rendered":"Autoregressive Conditional Heteroskedasticity"},"content":{"rendered":"<script type=\"application\/ld+json\">\r\n{\r\n  \"@context\": \"https:\/\/schema.org\",\r\n  \"@type\": \"ImageObject\",\r\n  \"@id\": \"https:\/\/analystprep.com\/study-notes\/images\/arch-example-img1\",\r\n  \"contentUrl\": \"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1-1536x782.jpg\",\r\n  \"url\": \"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1-1536x782.jpg\",\r\n  \"caption\": \"Autoregressive Conditional Heteroskedasticity (ARCH) Example\",\r\n  \"width\": 1536,\r\n  \"height\": 782,\r\n  \"copyrightNotice\": \"\u00a9 2024 AnalystPrep\",\r\n  \"acquireLicensePage\": \"https:\/\/analystprep.com\/license-info\",\r\n  \"creditText\": \"AnalystPrep Design Team\",\r\n  \"creator\": {\r\n    \"@type\": \"Organization\",\r\n    \"name\": \"AnalystPrep\"\r\n  },\r\n  \"isPartOf\": {\r\n    \"@type\": \"WebPage\",\r\n    \"@id\": \"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/\"\r\n  }\r\n}\r\n<\/script>\r\n\r\n<script type=\"application\/ld+json\">\r\n{\r\n  \"@context\": \"https:\/\/schema.org\",\r\n  \"@type\": \"QAPage\",\r\n  \"mainEntity\": {\r\n    \"@type\": \"Question\",\r\n    \"name\": \"What is the predicted variance for the next period in an ARCH(1) model?\",\r\n    \"text\": \"Consider the following regression results for an ARCH(1) model: Constant coefficient = 4.8347 with p-value < 0.001, and Lag 1 coefficient = 0.2678 with p-value < 0.001. Given that the current period squared error is 0.678, the predicted variance of the error terms in the next period is closest to: A. 4.835. B. 5.103. C. 5.016.\",\r\n    \"answerCount\": 3,\r\n    \"suggestedAnswer\": [\r\n      { \"@type\": \"Answer\", \"text\": \"A. 4.835\" },\r\n      { \"@type\": \"Answer\", \"text\": \"B. 5.103\" },\r\n      { \"@type\": \"Answer\", \"text\": \"C. 5.016\" }\r\n    ],\r\n    \"acceptedAnswer\": {\r\n      \"@type\": \"Answer\",\r\n      \"text\": \"The correct answer is C. In an ARCH(1) model, the predicted variance is calculated as sigma squared = alpha0 + alpha1 multiplied by the previous period squared error. Substituting the values gives 4.8347 + (0.2678 \u00d7 0.678) = 5.016.\"\r\n    },\r\n    \"author\": {\r\n      \"@type\": \"Organization\",\r\n      \"name\": \"AnalystPrep\"\r\n    }\r\n  }\r\n}\r\n<\/script>\r\n\r\n\r\n<h3 id=\"mce_22\" class=\"editor-rich-text__tinymce mce-content-body\" data-is-placeholder-visible=\"false\"><iframe loading=\"lazy\"\r\n  width=\"611\"\r\n  height=\"344\"\r\n  src=\"https:\/\/www.youtube.com\/embed\/-SilFtkpBK8\"\r\n  title=\"YouTube video player\"\r\n  frameborder=\"0\"\r\n  allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\"\r\n  referrerpolicy=\"strict-origin-when-cross-origin\"\r\n  allowfullscreen>\r\n<\/iframe>\r\n<\/h3>\r\n<p>Heteroskedasticity is the <strong>dependence<\/strong> of the <strong>variance of the error term<\/strong> on the <strong>independent variable.<\/strong> We have been assuming that time series follows the homoskedasticity assumption. Homoskedasticity is the <strong>independence <\/strong>of the variance of the error term on the independent variable. Violation of this condition leads to heteroskedasticity.<\/p>\r\n<p><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-14839\" src=\"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1.jpg\" alt=\"Homoskedasticity vs Heteroskedasticity\" width=\"1590\" height=\"809\" srcset=\"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1.jpg 1590w, https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1-300x153.jpg 300w, https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1-1024x521.jpg 1024w, https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1-768x391.jpg 768w, https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1-1536x782.jpg 1536w, https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1-400x204.jpg 400w\" sizes=\"auto, (max-width: 1590px) 100vw, 1590px\" \/>Heteroskedasticity<\/strong> in the autoregressive model makes the <strong>standard errors<\/strong> of the regression coefficients of the model i<strong>nvalid<\/strong>, leading to misleading interpretations.<\/p>\r\n<div style=\"margin: 18px 0;\"><a style=\"display: block; text-align: center; padding: 14px 18px; border: 2px solid #2F5BFF; border-radius: 18px; color: #ffffff ; font-weight: 600; font-size: 16px; text-decoration: none; background-color: #1a73e8 ;\" href=\"https:\/\/analystprep.com\/free-trial\/\" target=\"_blank\" rel=\"noopener noreferrer\"> Practice CFA Level II time-series concepts with our Free Trial.  <\/a><\/div>\r\n\r\n<h2>Autoregressive Conditional Heteroskedasticity (ARCH) Models<\/h2>\r\n<p>Autoregressive conditional heteroskedasticity is a problem associated with the correlation of variances of the error terms. An ARCH(1) model is an AR(1) model with conditional heteroskedasticity.<\/p>\r\n<p>The error terms in an ARCH(1) model are normally distributed with a mean of 0 and a variance of \\(\\text{a}_{0}+\\text{a}_{1}\\epsilon_{\\text{t}-1}^{2}\\).<\/p>\r\n<p>$$\\epsilon_{\\text{t}}\u223c\\text{N}(0, \\text{a}_{0}+\\text{a}_{1}\\epsilon_{\\text{t}-1}^{2})$$<\/p>\r\n<p><strong>Steps for Testing for ARCH(1) Conditional Heteroskedasticity<\/strong><\/p>\r\n<ol>\r\n\t<li>Regress the squared residuals from each period on the prior period squared residuals.<\/li>\r\n\t<li>Estimate \\(\\hat{\\epsilon}_{\\text{t}}^{2}=\\alpha_{0}+\\alpha_{1}\\hat{\\epsilon}_{\\text{t}-1}^{2}+\\mu_{\\text{t}}\\).<\/li>\r\n\t<li>If the estimated slope coefficient \u00a0\\(\\hat{\\alpha}_1\\) is statistically different from 0, the series shows an ARCH(1) effect, and thus the need to correct for heteroskedasticity.<\/li>\r\n\t<li>We can then predict the variance of the errors for time \\(t+1\\).<\/li>\r\n<\/ol>\r\n<h2>Predicting Variance<\/h2>\r\n<p>Given an ARCH(1) model, we can use the parameter estimates from our test for conditional heteroskedasticity to predict next period variance as:<\/p>\r\n<p>$$\\hat{\\sigma}_{\\text{t}+1}^{2}=\\hat{\\alpha}_{0}+\\hat{\\alpha}_{1}\\hat{\\epsilon}_{\\text{t}}^{2}$$<\/p>\r\n<h4>Example: Testing for ARCH (1) and Predicting the Variance of Errors<\/h4>\r\n<p>The following results have been obtained from regressing the squared residuals of an estimated autoregressive model on a constant and one lag of the squared error terms.<\/p>\r\n<h6 style=\"text-align: center;\">Regression Statistic<\/h6>\r\n<p>$$\\small{\\begin{array}{c|c} \\text{R-squared} &amp; 0.0430 \\\\ \\hline\\text{Standard error} &amp; 24.638 \\\\ \\hline\\text{Observations} &amp; 358 \\\\\u00a0 \\text{Durbin-Watson} &amp; 2.1021\\\\ \\hline\\end{array}}$$<\/p>\r\n<p>$$\\small{\\begin{array}{c|c|c|c} {}&amp;\\textbf{Coefficient}&amp;\\textbf{Standard Error}&amp;\\textbf{t-Statistic}\\\\ \\hline\\text{Intercept}&amp;9.1680&amp;1.4104&amp;6.55002\\\\ \\hline \\hat{\\epsilon}_{\\text{t}-1}^{2}&amp;0.2050&amp;0.0506&amp;4.0514\\\\\u00a0 \\end{array}}$$<\/p>\r\n<ol style=\"list-style-type: lower-alpha;\">\r\n\t<li>Test whether the original time series has ARCH(1) errors at the 5% significance level.<\/li>\r\n\t<li>If the squared error in the current period is 0.5%, predicted variance in the next period is <em>closest<\/em> to:<\/li>\r\n<\/ol>\r\n<p><strong>Solution<\/strong><\/p>\r\n<p>The test involves the <em><strong>first lag of the residuals<\/strong><\/em> of the approximated time series model, and thus the number of the observations is less by one. The number of degrees of freedom is \\(358-1=357\\), and the corresponding critical t-value at the 5% level of significance is 1.97.<\/p>\r\n<p>The <strong>t-statistic<\/strong> on \\(\\hat{\\epsilon}_{\\text{t}-1}^{2}\\) is <strong>greater than <\/strong>the<strong> critical value.<\/strong> This implies that \\(\\hat{\\alpha}_{1}\\) is statistically significantly different from 0. Therefore, the time series has ARCH(1) errors.<\/p>\r\n<p>The predicted variance for the next period is determined using the formula:<\/p>\r\n<p>$$\\hat{\\sigma}_{\\text{t}}^{2}=\\hat{\\alpha}_{0}+\\hat{\\alpha}_{1}\\hat{\\epsilon}_{\\text{t}-1}^{2}$$<\/p>\r\n<p>$$\\hat{\\sigma}_{\\text{t}}^{2}=9.1680+0.2050\\hat{\\epsilon}_{\\text{t}-1}^{2}$$<\/p>\r\n<p>So that the variance for the next period, in this case, is:<\/p>\r\n<p>$$\\hat{\\sigma}_{\\text{t}}^{2}=9.1680+0.2050\\times0.005=9.169025$$<\/p>\r\n<blockquote>\r\n<h2>Question<\/h2>\r\n<p>Consider the following regression results for an ARCH(1) model:<\/p>\r\n<p>$$\\small{\\begin{array}{c|c|c} {}&amp;\\textbf{Coefficients} &amp; \\textbf{P-value} \\\\ \\hline\\text{Constant} &amp; 4.8347 &amp; &lt;0.001 \\\\ \\hline\\text{Lag 1} &amp; 0.2678 &amp; &lt;0.001\\\\\u00a0 \\end{array}}$$<\/p>\r\n<p>Given that the current period squared error is 0.678, the predicted variance of the error terms in the next period is <em>closest<\/em> to:<strong>\u00a0<\/strong><\/p>\r\n<ol style=\"list-style-type: upper-alpha;\">\r\n\t<li>4.835.<\/li>\r\n\t<li>5.103.<\/li>\r\n\t<li>5.016.<\/li>\r\n<\/ol>\r\n<h4>Solution<\/h4>\r\n<p><strong>The correct answer is C.<\/strong><\/p>\r\n<p>The predicted variance for the next period is determined using the formula:<\/p>\r\n<p>$$\\hat{\\sigma}_{\\text{t}}^{2}=\\hat{\\alpha}_{0}+\\hat{\\alpha}_{1}\\hat{\\epsilon}_{\\text{t}-1}^{2}$$<\/p>\r\n<p>$$\\hat{\\sigma}_{\\text{t}}^{2}=4.8347+0.2678\\times0.678=5.016$$<\/p>\r\n<\/blockquote>\r\n<p>Reading 5: Time Series Analysis<\/p>\r\n<p><em>LOS 5 (m) Explain autoregressive conditional heteroskedasticity (ARCH) and describe how ARCH models can be applied to predict the variance of a time series.<\/em><\/p>\r\n<div style=\"text-align: center; margin: 30px 0;\"><a style=\"display: inline-flex; align-items: center; justify-content: center; padding: 12px 26px; border-radius: 9999px; background: #1e5bd8; color: #ffffff; font-weight: bold; text-decoration: none;\" href=\"https:\/\/analystprep.com\/free-trial\/\" target=\"_blank\" rel=\"noopener noreferrer\"> Start Free Trial \u2192 <\/a> <p style=\"margin-top: 12px; font-size: 16px; line-height: 1.5;\">Access CFA Level II quantitative methods study notes, practice questions, item sets, and video lessons to strengthen your understanding of autoregressive conditional heteroskedasticity.   <\/p>\r\n <\/div>\r\n\r\n","protected":false},"excerpt":{"rendered":"<p>Heteroskedasticity is the dependence of the variance of the error term on the independent variable. We have been assuming that time series follows the homoskedasticity assumption. Homoskedasticity is the independence of the variance of the error term on the independent&#8230;<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[102,229],"tags":[299,216,230],"class_list":["post-13522","post","type-post","status-publish","format-standard","hentry","category-cfa-level-2","category-quantitative-method","tag-autoregressive-conditional-heteroskedasticity","tag-cfa-level-2","tag-quantitative-method","blog-post","no-post-thumbnail","animate"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.6 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>ARCH Models &amp; Heteroskedasticity | AnalystPrep<\/title>\n<meta name=\"description\" content=\"Learn how ARCH models measure changing variance in time series data and forecast volatility in financial models.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"ARCH Models &amp; Heteroskedasticity | AnalystPrep\" \/>\n<meta property=\"og:description\" content=\"Learn how ARCH models measure changing variance in time series data and forecast volatility in financial models.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/\" \/>\n<meta property=\"og:site_name\" content=\"CFA, FRM, and Actuarial Exams Study Notes\" \/>\n<meta property=\"article:published_time\" content=\"2021-04-14T09:36:12+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-05-27T18:34:19+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1590\" \/>\n\t<meta property=\"og:image:height\" content=\"809\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Irene R\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Irene R\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"3 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/\"},\"author\":{\"name\":\"Irene R\",\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/#\\\/schema\\\/person\\\/7002f30d8f174958802c1c30b167eaf5\"},\"headline\":\"Autoregressive Conditional Heteroskedasticity\",\"datePublished\":\"2021-04-14T09:36:12+00:00\",\"dateModified\":\"2026-05-27T18:34:19+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/\"},\"wordCount\":662,\"image\":{\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/wp-content\\\/uploads\\\/2021\\\/02\\\/Img_1.jpg\",\"keywords\":[\"Autoregressive Conditional Heteroskedasticity\",\"CFA-level-2\",\"Quantitative Method\"],\"articleSection\":[\"CFA Level II Study Notes\",\"Quantitative Method\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/\",\"url\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/\",\"name\":\"ARCH Models & Heteroskedasticity | AnalystPrep\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/wp-content\\\/uploads\\\/2021\\\/02\\\/Img_1.jpg\",\"datePublished\":\"2021-04-14T09:36:12+00:00\",\"dateModified\":\"2026-05-27T18:34:19+00:00\",\"author\":{\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/#\\\/schema\\\/person\\\/7002f30d8f174958802c1c30b167eaf5\"},\"description\":\"Learn how ARCH models measure changing variance in time series data and forecast volatility in financial models.\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/#primaryimage\",\"url\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/wp-content\\\/uploads\\\/2021\\\/02\\\/Img_1.jpg\",\"contentUrl\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/wp-content\\\/uploads\\\/2021\\\/02\\\/Img_1.jpg\",\"width\":1590,\"height\":809,\"caption\":\"Homoskedasticity vs Heteroskedasticity\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/cfa-level-2\\\/autoregressive-conditional-heteroskedasticity\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Autoregressive Conditional Heteroskedasticity\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/#website\",\"url\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/\",\"name\":\"CFA, FRM, and Actuarial Exams Study Notes\",\"description\":\"Question Bank and Study Notes for the CFA, FRM, and Actuarial exams\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/#\\\/schema\\\/person\\\/7002f30d8f174958802c1c30b167eaf5\",\"name\":\"Irene R\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/33caf1e1bcb63ee970b36351f165c7bc714b19614993ab9c2c8bf36273b7df48?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/33caf1e1bcb63ee970b36351f165c7bc714b19614993ab9c2c8bf36273b7df48?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/33caf1e1bcb63ee970b36351f165c7bc714b19614993ab9c2c8bf36273b7df48?s=96&d=mm&r=g\",\"caption\":\"Irene R\"},\"url\":\"https:\\\/\\\/analystprep.com\\\/study-notes\\\/author\\\/irene\\\/\"}]}<\/script>\n<meta property=\"og:video\" content=\"https:\/\/www.youtube.com\/embed\/-SilFtkpBK8\" \/>\n<meta property=\"og:video:type\" content=\"text\/html\" \/>\n<meta property=\"og:video:duration\" content=\"3302\" \/>\n<meta property=\"og:video:width\" content=\"480\" \/>\n<meta property=\"og:video:height\" content=\"270\" \/>\n<meta property=\"ya:ovs:adult\" content=\"false\" \/>\n<meta property=\"ya:ovs:upload_date\" content=\"2021-04-14T09:36:12+00:00\" \/>\n<meta property=\"ya:ovs:allow_embed\" content=\"true\" \/>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"ARCH Models & Heteroskedasticity | AnalystPrep","description":"Learn how ARCH models measure changing variance in time series data and forecast volatility in financial models.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/","og_locale":"en_US","og_type":"article","og_title":"ARCH Models & Heteroskedasticity | AnalystPrep","og_description":"Learn how ARCH models measure changing variance in time series data and forecast volatility in financial models.","og_url":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/","og_site_name":"CFA, FRM, and Actuarial Exams Study Notes","article_published_time":"2021-04-14T09:36:12+00:00","article_modified_time":"2026-05-27T18:34:19+00:00","og_image":[{"width":1590,"height":809,"url":"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1.jpg","type":"image\/jpeg"}],"author":"Irene R","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Irene R","Est. reading time":"3 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/#article","isPartOf":{"@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/"},"author":{"name":"Irene R","@id":"https:\/\/analystprep.com\/study-notes\/#\/schema\/person\/7002f30d8f174958802c1c30b167eaf5"},"headline":"Autoregressive Conditional Heteroskedasticity","datePublished":"2021-04-14T09:36:12+00:00","dateModified":"2026-05-27T18:34:19+00:00","mainEntityOfPage":{"@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/"},"wordCount":662,"image":{"@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/#primaryimage"},"thumbnailUrl":"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1.jpg","keywords":["Autoregressive Conditional Heteroskedasticity","CFA-level-2","Quantitative Method"],"articleSection":["CFA Level II Study Notes","Quantitative Method"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/","url":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/","name":"ARCH Models & Heteroskedasticity | AnalystPrep","isPartOf":{"@id":"https:\/\/analystprep.com\/study-notes\/#website"},"primaryImageOfPage":{"@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/#primaryimage"},"image":{"@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/#primaryimage"},"thumbnailUrl":"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1.jpg","datePublished":"2021-04-14T09:36:12+00:00","dateModified":"2026-05-27T18:34:19+00:00","author":{"@id":"https:\/\/analystprep.com\/study-notes\/#\/schema\/person\/7002f30d8f174958802c1c30b167eaf5"},"description":"Learn how ARCH models measure changing variance in time series data and forecast volatility in financial models.","breadcrumb":{"@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/#primaryimage","url":"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1.jpg","contentUrl":"https:\/\/analystprep.com\/study-notes\/wp-content\/uploads\/2021\/02\/Img_1.jpg","width":1590,"height":809,"caption":"Homoskedasticity vs Heteroskedasticity"},{"@type":"BreadcrumbList","@id":"https:\/\/analystprep.com\/study-notes\/cfa-level-2\/autoregressive-conditional-heteroskedasticity\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/analystprep.com\/study-notes\/"},{"@type":"ListItem","position":2,"name":"Autoregressive Conditional Heteroskedasticity"}]},{"@type":"WebSite","@id":"https:\/\/analystprep.com\/study-notes\/#website","url":"https:\/\/analystprep.com\/study-notes\/","name":"CFA, FRM, and Actuarial Exams Study Notes","description":"Question Bank and Study Notes for the CFA, FRM, and Actuarial exams","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/analystprep.com\/study-notes\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/analystprep.com\/study-notes\/#\/schema\/person\/7002f30d8f174958802c1c30b167eaf5","name":"Irene R","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/33caf1e1bcb63ee970b36351f165c7bc714b19614993ab9c2c8bf36273b7df48?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/33caf1e1bcb63ee970b36351f165c7bc714b19614993ab9c2c8bf36273b7df48?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/33caf1e1bcb63ee970b36351f165c7bc714b19614993ab9c2c8bf36273b7df48?s=96&d=mm&r=g","caption":"Irene R"},"url":"https:\/\/analystprep.com\/study-notes\/author\/irene\/"}]},"og_video":"https:\/\/www.youtube.com\/embed\/-SilFtkpBK8","og_video_type":"text\/html","og_video_duration":"3302","og_video_width":"480","og_video_height":"270","ya_ovs_adult":"false","ya_ovs_upload_date":"2021-04-14T09:36:12+00:00","ya_ovs_allow_embed":"true"},"_links":{"self":[{"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/posts\/13522","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/comments?post=13522"}],"version-history":[{"count":35,"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/posts\/13522\/revisions"}],"predecessor-version":[{"id":43507,"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/posts\/13522\/revisions\/43507"}],"wp:attachment":[{"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/media?parent=13522"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/categories?post=13522"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/analystprep.com\/study-notes\/wp-json\/wp\/v2\/tags?post=13522"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}