{
 "key": "marshall1920",
 "url": "https://www.econlib.org/library/Marshall/marP.html",
 "final_url": "https://www.econlib.org/library/Marshall/marP.html",
 "status": 200,
 "content_type": "text/html; charset=UTF-8",
 "fetched": "2026-11-01",
 "bytes": 156181,
 "title": "Principles of Economics - Econlib",
 "date_modified": "2018-07-09",
 "text_sample": " (function(w, d, s, l, i) { w[l] = w[l] || []; w[l].push({ 'gtm.start': new Date().getTime(), event: 'gtm.js' }); var f = d.getElementsByTagName(s)[0], j = d.createElement(s), dl = l != 'dataLayer' ? '&l=' + l : ''; j.async = true; j.src = 'https://www.googletagmanager.com/gtm.js?id=' + i + dl; f.parentNode.insertBefore(j, f); })(window, document, 'script', 'dataLayer', 'GTM-P8T58BB'); Principles of Economics - Econlib {\"@context\":\"https:\\/\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\/\\/www.econlib.org\\/library\\/Marshall\\/marP.html\",\"url\":\"https:\\/\\/www.econlib.org\\/library\\/Marshall\\/marP.html\",\"name\":\"Principles of Economics - Econlib\",\"isPartOf\":{\"@id\":\"https:\\/\\/www.econlib.org\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\/\\/www.econlib.org\\/library\\/Marshall\\/marP.html#primaryimage\"},\"image\":{\"@id\":\"https:\\/\\/www.econlib.org\\/library\\/Marshall\\/marP.html#primaryimage\"},\"thumbnailUrl\":\"https:\\/\\/www.econlib.org\\/wp-content\\/uploads\\/2018\\/02\\/nonLFpub.jpg\",\"datePublished\":\"2018-02-05T02:04:19+00:00\",\"dateModified\":\"2018-07-09T20:24:52+00:00\",\"breadcrumb\":{\"@id\":\"https:\\/\\/www.econlib.org\\/library\\/Marshall\\/marP.html#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\/\\/www.econlib.org\\/library\\/Marshall\\/marP.html\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\/\\/www.econlib.org\\/library\\/Marshall\\/marP.html#primaryimage\",\"url\":\"https:\\/\\/www.econlib.org\\/wp-content\\/uploads\\/2018\\/02\\/nonLFpub.jpg\",\"contentUrl\":\"https:\\/\\/www.econlib.org\\/wp-content\\/uploads\\/2018\\/02\\/nonLFpub.jpg\",\"width\":1000,\"height\":710,\"caption\":\"Row of books. Background or texture\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\/\\/www.econlib.org\\/library\\/Marshall\\/marP.html#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\/\\/www.econlib.org\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Books\",\"item\":\"https:\\/\\/www.econlib.org\\/books\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Principles of Economics\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\/\\/www.econlib.org\\/#website\",\"url\":\"https:\\/\\/www.econlib.org\\/\",\"name\":\"Econlib\",\"description\":\"The Library of Economics and Liberty\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\/\\/www.econlib.org\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"}]} img:is([sizes=auto i],[sizes^=\"auto,\" i]){contain-intrinsic-size:3000px 1500px} /*# sourceURL=wp-img-auto-sizes-contain-inline-css */ img.wp-smiley, img.emoji { display: inline !important; border: none !important; box-shadow: none !important; height: 1em !important; width: 1em !important; margin: 0 0.07em !important; vertical-align: -0.1em !important; background: none !important; padding: 0 !important; } /*# sourceURL=wp-emoji-styles-inline-css */ :root{--wp-block-synced-color:#7a00df;--wp-block-synced-color--rgb:122,0,223;--wp-bound-block-color:var(--wp-block-synced-color);--wp-editor-canvas-background:#ddd;--wp-admin-theme-color:#007cba;--wp-admin-theme-color--rgb:0,124,186;--wp-admin-theme-color-darker-10:#006ba1;--wp-admin-theme-color-darker-10--rgb:0,107,160.5;--wp-admin-theme-color-darker-20:#005a87;--wp-admin-theme-color-darker-20--rgb:0,90,135;--wp-admin-border-width-focus:2px}@media (min-resolution:192dpi){:root{--wp-admin-border-width-focus:1.5px}}.wp-element-button{cursor:pointer}:root .has-very-light-gray-background-color{background-color:#eee}:root .has-very-dark-gray-background-color{background-color:#313131}:root .has-very-light-gray-color{color:#eee}:root .has-very-dark-gray-color{color:#313131}:root .has-vivid-green-cyan-to-vivid-cyan-blue-gradient-background{background:linear-gradient(135deg,#00d084,#0693e3)}:root .has-purple-crush-gradient-background{background:linear-gradient(135deg,#34e2e4,#4721fb 50%,#ab1dfe)}:root .has-hazy-dawn-gradient-background{background:linear-gradient(135d"
}