How common are common priors?

To answer the question in the title we vary agents? beliefs against the background of a fixed knowledge space, that is, a state space with a partition for each agent. Beliefs are the posterior probabilities of agents, which we call type profiles. We then ask what is the topological size of the set of consistent type profiles, those that are derived from a common prior (or a common improper prior in the case of an infinite state space). The answer depends on what we term the tightness of the partition profile. A partition profile is tight if in some state it is common knowledge that any increase of any single agent?s knowledge results in an increase in common knowledge. We show that for partition profiles that are tight the set of consistent type profiles is topologically large, while for partition profiles that are not tight this set is topologically small.     

AN APPROACH TO THE ECONOMETRIC ESTIMATION OF ATTITUDES TO RISK IN AGRICULTURE: COMMENT

Bardsley and Harris (1987) test empirically the effects of changes In deterministic wealth and random income on the measure partial risk aversion. The paper, which is otherwise well written, failed to impose the relationship between the two effects and estimated them independently. Consequently, inconsistent estimates were derived for the elasticities of the measure of partial risk aversion with respect to wealth and to income. The purpose of this comment is to derive that relationship theoretically and to point out the resulting inconsistencies in the original paper.     

Block-Rate versus Uniform Water Pricing in Agriculture: An Empirical Analysis

In this article we adapt Burtless and Hausman's (1978) methodology in order to estimate farmers' demand for irrigation water under increasing block-rate tariffs and empirically assess its effect on aggregate demand and inter-farm allocation efficiency. This methodology overcomes the technical challenges raised by increasing block-rate pricing and accounts for both observed and unobserved technological heterogeneity among farmers. Employing micro panel data documenting irrigation levels and prices in 185 Israeli agricultural communities in the period 1992–1997, we estimate water demand elasticity at −0.3 in the short run (the effect of a price change on demand within a year of implementation) and −0.46 in the long run. We also find that, in accordance with common belief, switching from a single to a block-price regime, yields a 7% reduction in average water use while maintaining the same average price. However, based on our simulations we estimate that the switch to block prices will result in a loss of approximately 1% of agricultural output due to inter-farm allocation inefficiencies.     

Weakly rational expectations

Aumann and Drèze (2008) characterised the set of interim expected payoffs that players may have in rational belief systems, in which there is common knowledge of rationality and a common prior. We show here that common knowledge of rationality is not needed: when rationality is satisfied in the support of an action-consistent distribution (a concept introduced by Barelli (2009)), one obtains exactly the same set of rational expectations, despite the fact that in such ‘weakly rational belief systems’ there may not be mutual knowledge of rationality, let alone common knowledge of rationality. In the special case of two-player zero-sum games, the only expected payoff is the minmax value, even under these weak assumptions.     

Comparing Alternative Hedge Accounting Standards: Shareholders' Perspective

We study the economic consequences of alternative hedge accounting rules in terms of managerial hedging decisions and wealth effects for shareholders. The rules we consider include the fair-value and cash-flow hedge accounting methods prescribed by the recent SFAS No. 133. We illustrate that the accounting method used influences the manager's hedge decision. We show that under no-hedge accounting, the hedge choice is different from the optimal economic hedge the firm would make under symmetric and public information. However, under a certain definition of fair-value hedge accounting, the hedging decision preserves the optimal economic hedge. We then demonstrate that long-term and future shareholders prefer a certain definition of fair-value hedge accounting to no-hedge accounting, while short-term shareholders prefer either approach depending on risk preferences and the level of uncertainty. We speculate about circumstances in which a manager would choose not to adopt fair-value hedge accounting when he has the option not to do so.     

Monitoring in Multiagent Organizations*

This paper studies how to assign “monitors” to productive agents in order to generate signals about the agents' performance that are most useful from a contracting perspective. We show that if signals generated by the same monitor are negatively (positively) correlated, then the optimal monitoring assignment will be “focused” (“dispersed”). This holds because dispersed monitoring allows the firm to better utilize relative performance evaluation. On the other hand, if each monitor communicates only an aggregated signal to the principal, then focused monitoring is always optimal since aggregation undermines relative performance evaluation. We also study team‐based compensation and randomized monitoring assignments. In particular, we show that the firm can gain from randomizing the monitoring assignment, compared with the optimal linear deterministic contract. Furthermore, under randomization, the conditional expected utility for the agent is higher when the agent is not monitored compared with the case where the agent is monitored. That is, the chance of being monitored serves as a “stick” rather than a “carrot”.     

Cross-Country Productivity Comparisons: The “Revealed Superiority” Approach

This paper proposes a novel non-parametric methodology for comparing total factor productivity (TFP) across countries and over time. It develops the principle of revealed superiority along the lines of Samuelson's principle of revealed preferences. Specifically, we compare the aggregate actual profits in each country to the hypothetical profits it would have earned if, facing its own prices, it had employed another country's inputs and produced its output. We show that our procedure reveals the true TFP ranking under relatively mild assumptions. We apply our method by ranking a panel of the 25 richest economies relative to one another and over time and find that the United States enjoys the highest TFP whereas Singapore has the lowest.     

Dividend Changes and Future Profitability

We investigate the relation between dividend changes and future profitability, measured in terms of either future earnings or future abnormal earnings. Supporting "the information content of dividends hypothesis," we find that dividend changes provide information about the level of profitability in subsequent years, incremental to market and accounting data. We also document that dividend changes are positively related to earnings changes in each of the two years after the dividend change.     

Performance Evaluation and Corporate Income Taxes in a Sequential Delegation Setting

We consider a setting where a firm delegates an investment decision and, subsequently, a sales decision to a privately informed manager. For both decisions corporate income taxes have real effects. We show that compensating the manager based on pre-tax residual income can ensure after-tax NPV-maximization (goal congruence) for each decision problem in isolation. However, this metric fails if both decisions are nontrivial, since it requires asset-specific hurdle rates and hence precludes asset aggregation. After-tax residual income metrics (e.g., EVA) allow the firm to consistently apply its after-tax cost of capital as the hurdle rate to its aggregate asset base. We show that existing tax depreciation schedules may explain why firms in practice use more accelerated depreciation schedules than those suggested by previous studies. Our findings also rationalize the widespread use of dirty surplus accounting for windfall gains and losses for managerial retention purposes.