{"id":886,"date":"2015-01-17T14:32:20","date_gmt":"2015-01-17T20:32:20","guid":{"rendered":"http:\/\/www.ssc.wisc.edu\/~jfrees\/?page_id=886"},"modified":"2015-02-20T17:23:09","modified_gmt":"2015-02-20T23:23:09","slug":"4-recursive-calculations-policy-values-with-annual-cash-flows","status":"publish","type":"page","link":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/actuarial-mathematics\/policy-values\/4-recursive-calculations-policy-values-with-annual-cash-flows\/","title":{"rendered":"4. Recursive Calculations: Policy Values with Annual Cash Flows"},"content":{"rendered":"<p>Begin with the expression for the general discrete policy and split off the first year<br \/>\n\\begin{eqnarray*}<br \/>\n_h V &#038;=&#038; b_{h+1} v q_{x+h} &#8211; P_h+<br \/>\n\\sum_{s=0}^{\\infty} \\left\\{b_{h+s+1} v^{s+2} ~_{s+1|} q_{x+h} &#8211; P_{h+s+1} v^{s+1} ~_{s+1} p_{x+h} \\right\\}<br \/>\n\\end{eqnarray*}where we have used \\(s=j-1\\). Now, recall the relation \\(~_{s+1} p_{x+h}= p_{x+h} ~_s p_{x+h+1}\\) and<br \/>\n\\begin{eqnarray*}<br \/>\n~_{s+1|} q_{x+h} &#038;=&#038; ~_{s+1} p_{x+h} q_{x+h+s+1} \\\\<br \/>\n&#038;=&#038; p_{x+h} ~_s p_{x+h+1} q_{x+h+s+1} = p_{x+h} ~_{s|} q_{x+h+1}<br \/>\n\\end{eqnarray*}<br \/>\nWith this, we have<br \/>\n\\begin{eqnarray*}<br \/>\n_h V &#038;=&#038; b_{h+1} v q_{x+h} &#8211; P_h+<br \/>\nvp_{x+h} \\sum_{s=0}^{\\infty} \\left\\{b_{h+1+s} v^{s+1} ~_{s|} q_{x+h+1} &#8211; P_{h+1+s} v^s ~_s p_{x+h+1} \\right\\} \\\\<br \/>\n&#038;=&#038; b_{h+1} v q_{x+h} &#8211; P_h+ vp_{x+h} ~_{h+1} V.<br \/>\n\\end{eqnarray*}<br \/>\nPut another way, we can express this as<\/p>\n<table align=\"center\" border=\"0\">\n<tbody>\n<tr>\n<td style=\"background-color: #ffffff\"> <font size=\"4\">\\(_h V+P_h\\)<\/font><\/td>\n<td style=\"background-color: #ffffff\">     <font size=\"4\">\\(= v  q_{x+h} b_{h+1}\\)<\/font><\/td>\n<td style=\"background-color: #ffffff\"> <font size=\"4\"> \\(+vp_{x+h} ~_{h+1} V\\)<\/font><\/td>\n<\/tr>\n<tr>\n<td align=\"center\">\n\t\t\t<font size=\"4\">policy value  <\/font><br \/>\n\t\t\t<font size=\"4\">plus premium<\/font><br \/>\n\t\t\t&nbsp;\n\t\t\t<\/td>\n<td align=\"center\">\n\t\t\t<font size=\"4\">is sufficient to provide a        <\/font><br \/>\n\t\t\t<font size=\"4\"> death benefit for the<\/font><br \/>\n\t\t\t<font size=\"4\">proportion that fails<\/font>\n\t\t\t<\/td>\n<td align=\"center\">\n\t\t\t<font size=\"4\"> plus the policy value<\/font><br \/>\n\t\t\t<font size=\"4\">for the proportion<\/font><br \/>\n\t\t\t<font size=\"4\">that survives<\/font>\n\t\t\t<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Example<\/strong><br \/>\nConsider a special fully discrete 10- year endowment policy to (30). Level premiums are payable for 10 years. The maturity value is 1 and a level \\(i=6\\%\\) interest is assumed. For simplicity, mortality is given as \\(~_k p_{30} = 0.98^k\\). The death benefit is 1 plus the policy value. Calculate \\(V_3\\).<\/p>\n<p><em>Solution.<\/em><\/p>\n<p>Using the recursive reserve formulation, we have<br \/>\n\\begin{eqnarray*}<br \/>\n(1.06)(_h V + P) &#038;=&#038; b_{h+1} q_{x+h} + p_{x+h} ~_{h+1} V \\\\<br \/>\n&#038;=&#038; (1+ ~_{h+1} V) q_{x+h} + p_{x+h} ~_{h+1} V = 0.02 + ~_{h+1} V<br \/>\n\\end{eqnarray*}<br \/>\nbecause \\( q_{x+h}=1-p_{x+h}=1- \\frac{~_{h+1} p_x}{~ _h p_x} = 0.02\\). We re-write this as<br \/>\n\\begin{eqnarray*}<br \/>\n1.06 ~_h V &#8211; ~_{h+1} V &#038;=&#038; q_{x+h} &#8211; 1.06 P<br \/>\n\\end{eqnarray*}<br \/>\nMultiplying each side by \\(v^{h+1}\\) yields<br \/>\n\\begin{eqnarray*}<br \/>\nv^h ~_h V &#8211; v^{h+1} ~_{h+1} V &#038;=&#038; v^{h+1} q_{x+h} &#8211; v^h P .<br \/>\n\\end{eqnarray*}<br \/>\nSumming both sides over \\(h=0, \\ldots, 9\\) yields<br \/>\n\\begin{eqnarray*}<br \/>\nv^0 ~_0 V &#8211; v^{10} ~_{10} V &#038;=&#038; \\sum_{h=0}^9 \\left( v^{h+1} q_{x+h} &#8211; v^h P \\right)\\\\<br \/>\n&#038;=&#038; (v(0.02) &#8211; 1.06 P) \\ddot{a}_{\\overline{10|}}<br \/>\n\\end{eqnarray*}<br \/>\nBecause \\(_0 V=0\\) and \\(_{10} V=1\\), we have<br \/>\n\\begin{eqnarray*}<br \/>\nP &#038;=&#038; \\frac{v^{10}}{\\ddot{a}_{\\overline{10|}}} +0.02 v = 0.09044.<br \/>\n\\end{eqnarray*} <\/p>\n<p><div class=\"alignleft\"><a href=\"https:\/\/users.ssc.wisc.edu\/~ewfrees\/actuarial-mathematics\/policy-values\/3-policy-values-with-annual-cash-flows-eqnarray-not-working\/\" title=\"3. Policy Values with Annual Cash Flows\">&#9668 Previous page<\/a><\/div><div class=\"alignright\"><a href=\"https:\/\/users.ssc.wisc.edu\/~ewfrees\/actuarial-mathematics\/policy-values\/888-2\/\" title=\"5. Expense Augmented Policy Values\">Next page &#9658<\/a><\/div><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Begin with the expression for the general discrete policy and split off the first year \\begin{eqnarray*} _h V &#038;=&#038; b_{h+1} v q_{x+h} &#8211; P_h+ \\sum_{s=0}^{\\infty} \\left\\{b_{h+s+1} v^{s+2} ~_{s+1|} q_{x+h} &#8211; P_{h+s+1} v^{s+1} ~_{s+1} p_{x+h} \\right\\} &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":280,"menu_order":3,"comment_status":"closed","ping_status":"open","template":"","meta":{"jetpack_post_was_ever_published":false},"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/P8cLPd-ei","acf":[],"_links":{"self":[{"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/pages\/886"}],"collection":[{"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/comments?post=886"}],"version-history":[{"count":4,"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/pages\/886\/revisions"}],"predecessor-version":[{"id":1568,"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/pages\/886\/revisions\/1568"}],"up":[{"embeddable":true,"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/pages\/280"}],"wp:attachment":[{"href":"https:\/\/users.ssc.wisc.edu\/~ewfrees\/wp-json\/wp\/v2\/media?parent=886"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}