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 Students / Subjects  UL Literature Autorenkollektiv (1997), Bogart (1985), Funk & Stoer (1997), Hausmeister (1952), Lotterbottel (1983)   Source: SFB 504 ultimatum game An experiment. There are two players, an allocator A and a recipient R, who in the experiment do not know one another. They have received a windfall, e.g., of \$1. The allocator, moving first, proposes to split the windfall by proposing to take share x, so that A receives x and R receives 1-x. The recipient can accept this allocation, or reject it in which case both get nothing. The subgame perfect equilibrium outcome is that A would offer the smallest possible amount to R, e.g., the share \$.99 for A and \$.01 for R, and that the recipient should accept. The experimental evidence, however, is that A offers a relatively large share to R, often 50-50, and that R would often reject smaller positive amounts. We may interpret R's behavior has willingness to pay a cost to punish "unfair" splits. With regard to A's behavior -- does A care about fairness too? Or is A income-maximizing given R's likely behavior? See also Dictator Game. Source: econterms unbalanced data In a panel data set, there are observations across cross-section units (e.g. individuals or firms), and across time periods. Often such a data set can be represented by a completely filled in matrix of N units and T periods. In the "unbalanced data" case, however, the number of observations per time period varies. (Equivalently one might say that the number of observations per unit is not always the same.) One might handle this by letting T be the total number of time periods and Nt be the number of observations in each period. Source: econterms unbiased An estimator b of a distribution's parameter B is unbiased if the mean of b's sampling distribution is B. Formally, if: E[b] = B. Source: econterms uncertainty If outcomes will occur with a probability that cannot even be estimated, the decisionmaker faces uncertainty. Contrast risk. This meaning to uncertainty is attributed to Frank Knight, and is sometimes referred to as Knightian uncertainty. The decisionmaker can apply game theory even in such a circumstance, e.g. the choice of a dominant strategy. Kreps (1988), p 31, writes that three standard ways of modeling choices made under conditions of uncertainty are with von Neumann-Morgenstern expected utility over objective uncertainty, the Savage axioms for modeling subjective uncertainty, and the Anscombe-Aumann theory which is a middle course between them. A recent ad for a new book edited by Haim Levy (Stochastic Dominance: Investment Decision Making under Uncertainty) considers three ways of modeling investment choices under uncertainty: by tradeoffs between mean and variance, by choices made by stochastic dominance, and non-expected utility approaches using prospect theory. Source: econterms uncorrelated Two random variables X and Y are uncorrelated if E(XY)=E(X)E(y). Note that this does not guarantee they are independent. Source: econterms under the null Means "assuming the hypothesis being tested is true." Source: econterms unemployment The state of an individual looking for a paying job but not having one. Does not include full-time students, the retired, children, or those not actively looking for a paying job. Source: econterms uniform distribution A continuous distribution over a range which we will denote [a,b]. Pdf is (x-a)/(b-a). Mean is .5*(a+b). Variance is (1/12)(b-a)2. Source: econterms uniform kernel The uniform kernel function is 1/2, for -1