From WSJ.com: How to Get to Retirement? Practice! - WSJ.com
"Working through your 60s, even if only part time, allows you to spend from your wages instead of your savings, she explains. This gives your nest egg more time to grow and shortens the time you'll need to support yourself on savings alone.
It also allows you to delay taking Social Security benefits and to scale back, or even discontinue, contributions to your 401(k) retirement plan.
As for your 401(k), she says contributions in your 60s are the least important because there's less time for them to compound, so you should consider contributing only enough to qualify for any employer matching contributions."
Be sure to review the Comment Section for some counter-arguments and more balanced view for working longer past 65 as well as delaying social security benefits.
I think that it is to each her/his own. Many cannot work part-time during retirement and many cannot even have a job and have to take early retirement. It is not an academic analysis.
People die early as well. What if one delays taking social security till 70 but dies the next day?? What if the social security fund runs out earlier than the "plan"? Come on, let's be realistic -- it is a real world; not that one can plan ahead in an optimal and prophetic manner!!
Tom Johnson's comment (in the Comment Section) sums it up:
"Practice? Practice being debt free before retiring. Practice living on the lowest estimated income from all your potential sources and while you are at it, practice living on half of your estimated income. Practice saving while you are working. Once you do that, the extra savings, the extra SS income from deferrment, and the income that exceeds your expenses becomes money that allows you to take the trips and spoil the grandkids without having to stress about your finances."
I would add: "PRACTICE ENJOYING LIFE AND APPRECIATING/LOVING THE PEOPLE (E.G. FAMILY) AROUND YOU."