Many excellent writers, including some law clerks and former law clerks, take the position that an " 's " must be added to a name ending in "s" when using the possessive form. Strunk and White so command. William Strunk, Jr. & E. B. White, The Elements of Style 1 (3d ed. 1979). Others never add an " 's ". There is also authority permitting what might be called a hybrid approach: adding an " 's " when the "s" in the possessor's name sounds like an "s" but omitting the "s" where (as here) the sound of the "s" in the possessor's name is "z." The Chicago Manual of Style § 6.30 (Univ. of Chi. Press, 14th ed. 1993).United States v. Dinkins, 546 F. Supp. 2d 308, 309 n.1 (D. Md. 2008).
For example, during the top of an inning at Camden Yards, "Markakis's catches" in right may be applauded while "Jones' throws" from center are cheered. This hybrid approach has the virtue of marrying the written word and the spoken tongue and contributes to the growth of English as a living language, unconstrained by archaic and inflexible rules.
The Supreme Court is divided on this important issue. See Kansas v. Marsh, 126 S. Ct. 2516 (2006) (Thomas, J.) (omitting "s" when using the possessive form of words ending in "s"); id. at 2541 (Souter, J., dissenting) (adding "s" universally to the possessive form of words ending in "s"); id. at 2529 (Scalia, J., concurring) (following the hybrid approach). Presumably, my adoption of the hybrid approach is subject to a deferential standard of review, even by those more classically inclined.
The Winter 2009 edition of the Green Bag also announces that publication's formation of a "fantasy" or rotisserie league in which team owners will pick members of Congress based on their anticipated scores in categories such as:
Bills passing Senate
Bills passing House
Bills signed/survived veto
Earmarks per capita
Campaign contributions per capita
Press releases issued
Hill publication appearances
Television talk-show appearances
Colbert Report/Daily Show appearances
The league is called FantasyLaw. It doesn't yet but will soon have its own web site here. For now, you can find a description of the entire enterprise here.