The Orbit of the L dwarf + T dwarf Spectral Binary SDSS J080531.84+481233.0

[abridged] We report four years of radial velocity monitoring observations of SDSS J080531.84+481233.0 that reveal significant and periodic variability, confirming the binary nature of the source. We infer an orbital period of 2.02$\pm$0.03 yr, a semi-major axis of 0.76$^{+0.05}_{-0.06}$ AU, and an eccentricity of 0.46$\pm$0.05, consistent with the amplitude of astrometric variability and prior attempts to resolve the system. Folding in constraints based on the spectral types of the components (L4$\pm$0.7 and T5.5$\pm$1.1), corresponding effective temperatures, and brown dwarf evolutionary models, we further constrain the orbital inclination of this system to be nearly edge-on (90$^o\pm$19$^o$), and deduce a large system mass ratio (M$_2$/M$_1$ = 0.86$^{+0.10}_{-0.12}$), substellar components (M$_1$ = 0.057$^{+0.016}_{-0.014}$ M$_{\odot}$, M$_2$ = 0.048$^{+0.008}_{-0.010}$ M$_{\odot}$), and a relatively old system age (minimum age = 4.0$^{+1.9}_{-1.2}$ Gyr). The measured projected rotational velocity of the primary ($v\sin{i}$ = 34.1$\pm$0.7 km/s) implies that this inactive source is a rapid rotator (period $\lesssim$ 3 hr) and a viable system for testing spin-orbit alignment in very-low-mass multiples. The combination of well-determined component atmospheric properties and masses near and/or below the hydrogen minimum mass make SDSS J0805+4812AB an important system for future tests of brown dwarf evolutionary models.Comment: 15 pages, 11 figures, accepted for publication to Ap

The Adequacy of Investment Choices Offered By 401K Plans

Defined-contribution plans represent a major organizational form for investors’ retirement savings. Today more than one third of all workers are enrolled in 401K plans. In a 401K plan, participants select assets from a set of choices designated by an employer. For over half of 401K-plan participants, retirement savings represent their sole financial asset. Yet to date there has been no study of the adequacy of the choices offered by 401K plans. This paper analyzes the adequacy and characteristics of the choices offered to 401K-plan participants for over 400 plans. We find that, for 62% of the plans, the types of choices offered are inadequate, and that over a 20-year period this makes a difference in terminal wealth of over 300%. We find that funds included in the plans are riskier than the general population of funds in the same categories. We study the characteristics of plans that are associated with adequate investment choices, including an analysis of the use of company stock, plan size, and the use of outside consultants. When we examine one category of investment choices, S&P 500 index funds, we find that the index funds chosen by 401K-plan administrators are on average inferior to the S&P 500 index funds selected by the aggregate of all investors

Marginal Stockholder Tax Effects and Ex-Dividend Day Behavior-Thirty-Two Years Later

In 1970 Elton and Gruber (hereafter E&G) started an industry by studying the impact of taxes on investor decisions using the behavior of share prices around the ex-dividend date. E&G showed that if taxes enter investors’ decisions, then the fall in price on the ex-dividend day should reflect the post-tax value of the dividend relative to the post-tax value of capital gains on that day. Because dividends in most time periods are taxed more heavily than capital gains, the theory suggests that if taxes affect investor’s choices, the fall in stock price should in general be less than the dividend

How to Earn and Lose Your Constituency: A Case Study of New Jersey\u27s Fifth Congressional District

In 2016, Donald Trump inspired a red wave of voting that granted the Republicans control of the House and Senate for the first time since 2006. This seemingly should be a great time to be a Republican incumbent, especially in a Republican district. However, Scott Garrett, a long term conservative incumbent in New Jersey\u27s fifth congressional district, fell to Josh Gottheimer, a Clinton-backed Democrat. So what happened? I conclude that Garrett fails to capture a new base that comes into his district after redistricting, loses his original base after failing to correctly achieve a Dual Constituency approach, and is hindered by bad public perception following regrettable comments

Participant Reaction and The Performance of Funds Offered by 401(k) Plans

This is the first study to examine both how well plan administrators select funds and how participants react to plan administrator decisions. We find that on average administrators select funds that outperform randomly selected funds of the same type. When administrators change offerings, they choose funds that did well in the past, but after the change deleted funds do better than added funds. Plan participants react strongly to past performance in their allocation decisions. This accentuates the changes in allocation caused by returns. Participant allocations do no better than naïve allocation rules such as equal investment in each offering