Discrepancies between ex ante and ex post efficiency under identical subjective probabilities

Summary. Starr (1973) showed that, if people have different subjective probabilities, ex ante and ex post efficiency conflict. Conversely, under the simple preferences that he considered, the discrepancy between ex ante and ex post efficiency disappears when subjective probabilities are identical. Here I consider identical subjective probabilities, but more general preferences. First, risk attraction is admitted. Second, I dispense with the double requirement (dubbed IZU) of additive separability and state-independence of the utility of zero-date consumption, an unrealistic requirement when modeling the investment in durable goods. I find that, under IZU, and as long as ex post preferences satisfy the natural assumption of quasiconcavity (and satisfy some technical qualifications), an ex ante efficient allocation is indeed ex post efficient, but the converse is not necessarily true under risk attraction. If, on the other hand, IZU is violated, then one can have ex ante efficient allocations that are not ex post efficient, and vice-versa, even under risk aversion. Received: June 25, 1999; revised version: March 2001     

Hybrid Contests

This paper examines hybrid contests where participants commit two types of resources to improve their probability of winning the prize. The first type is forfeited ex ante, before the prize is allocated, by winners and losers alike, while the second is committed ex ante by all contenders but expended ex post, after the prize is allocated, and only by the contestant that wins the prize. The model yields a number of interesting results. Among them is the finding that, as the number of contestants increases, the ex ante expenditures of individual contestants decrease while the ex post expenditure increases. Even more interesting, the total of the ex ante and ex post expenditures by the contenders in a hybrid contest may decrease with the number of competitors. The study also finds that there is no rent overdissipation, and compares the total expenditures in the contest and “all‐pay” allocation mechanisms.     

Are you hiring Johnny Football or Johnny Doe? Uncertain labour quality and the measurement of monopsony in college football

I assess monopsony in the college football labour market as it relates to both typical and elite performers, while also accounting for the uncertain performance quality of prospective players who are in this labour market. Existing studies suggest that the marginal revenue product (MRP) of elite collegiate players later drafted into the National Football League (NFL), significantly exceeds their compensation. These comparisons overstate monopsony rents because schools don’t know ex ante which prospects will become these elite performers. Using financial data spanning 2004–2011 from 114 major schools, I estimate the MRP of players sorted into three ex post quality tiers, and find that while eventual NFL draftees generate revenue that significantly exceeds their compensation, a majority of scholarship players do not. Then, using Rivals.com talent ratings of 6,604 prospective players recruited from 2002–2008, I estimate the probability that prospects will reach each ex post quality tier given their ex ante ratings. MRP estimates are adjusted by these conditional probability estimates to reflect the expected MRP of prospects, which allows more appropriate assessment of monopsony rents. I find that schools possess substantially less monopsony power than unadjusted MRP estimates suggest.     

MEASURING VARIATIONS IN LIFETIME WELFARE EX ANTE AND EX POST: SOME EXPLORATORY CALCULATIONS

Whereas longevity‐adjusted consumption measures have become increasingly used as indicators of lifetime standards of living, it remained unnoticed that those measures, by relying on period – rather than cohort – life tables, constitute indicators of expected – rather than actual – lifetime standards of living. In order to estimate the actual gap between ex ante and ex post measures of lifetime welfare, this paper computes, for 19th‐century European economies, longevity‐adjusted consumption measures based on period and cohort life tables. It is shown that the gap between ex ante and ex post measures is statistically significant, and that attempts to reduce it are likely to be unsuccessful, because standards of living tend to exhibit, over temporal horizons as long as a human life, structural breaks, which make the ex ante measurement of lifetime welfare highly speculative.     

Uncertainty,Learning and Heterogeneity in International Environmental Agreements

This paper concerns the formation of International Environmental Agreements under uncertainty about environmental damage with different models of learning (complete learning, partial learning or no learning). The results of the existing literature are generally pessimistic: the possibility of either complete or partial learning generally reduces the level of global welfare that can be achieved from forming an IEA relative to no learning. That literature regards uncertainty as a parameter common to all countries, so that countries are identical ex ante as well as ex post. In this paper we extend the literature to the case where there is no correlation between damage costs across countries; each country is uncertain about a particular parameter (in our case the benefit-cost ratio) drawn from a common distribution but, ex post, each country’s realized parameter value is independently drawn. Consequently, while countries remain identical ex ante, they may be heterogeneous ex post. We show that this change reinforces the negative conclusions about the effects of partial learning on international environmental agreements, but, under certain conditions, moderates the negative conclusions about the effects of complete learning.     

Fiscal Policy in Real Time*

In this paper, I estimate the ex ante or intentional cyclical stance of fiscal policy in OECD countries. I use the fiscal plans reported at the time of budgeting, together with other information available to fiscal policy‐makers in real time. Indeed, fiscal plans might be significantly different from ex post outcomes because governments do not have complete control over their implementation, which is influenced by several exogenous factors. When fiscal‐policy rules are estimated using real‐time data, I show in this paper that OECD countries have often planned a counter‐cyclical fiscal stance, especially during economic expansions. This contrasts with conventional findings based on actual data, which tend to point towards a‐cyclicality or pro‐cyclicality. Forecast errors for the government structural balance and the output gap play a central role in explaining the differences between estimates based on ex ante and ex post data.     

Vertical integration and transaction-specific sunk costs

The purpose of this paper is to analyze vertical integration, long-term contracts and spot markets as institutional alternatives when transaction-specific investments are involved. Firm activities are divided into two periods. In the first period (the ex ante world), decisions on the amount of transaction-specific sunk costs are made, whereas after realization of a random state of the world, short-run production decisions are made (in the ex post world). The problem analyzed is to determine what form of organizations and/or contracts will emerge between upstream and downstream firms in the ex ante world to regulate their ex ante transaction-specific investments, if any, as well as their ex post production decisions and the distribution of resulting profits.     

Optimal Universal and Categorical Benefit Provision with Classification Errors and Imperfect Enforcement

We determine the optimal combination of a universal benefit and categorical benefit when individuals differ in their ability to work and, if able to work, their productivity. The categorical benefit is conditioned ex ante on applicants being unable to work and ex post on recipients not working. The awards test makes Type I/II errors. If the ex post condition is (i) not enforced, the optimal categorical benefit is positive only if the awards test has discriminatory power, while maximum welfare falls with both error propensities; but if (ii) fully enforced, the optimal categorical benefit is positive always and maximum welfare can increase with the Type II error propensity.     

Exploring causal relationships in an innovation program with Robust Portfolio Modeling

Many countries seek to foster the commercial exploitation of science-based research results through selective policy instruments. Typically, these instruments involve processes of follow-up data collection where the results of ex ante and ex post assessments are systematically recorded. Yet, several factors – such as the presence of multiple objectives, predominance of qualitative data and missing observations – may complicate the use of such data for adjusting the management practices of these instruments. With the aim of addressing these challenges, we adopt Robust Portfolio Modeling¹ (RPM) as an evaluation framework to the analysis of longitudinal data: specifically, we (i) determine subsets of outperforming and underperforming projects through the development of an explicit multicriteria model for ex post evaluation, and (ii) carry out comparative analyses between these subsets, in order to identify which ex ante interventions and contextual characteristics may have contributed to later performance. We also report experiences from the application of RPM-evaluation to a Finnish innovation program and outline extensions of this approach that provide further decision support to the managers of innovation programs.     

累积创新中的内生许可证

This paper analyzes the endogeneity of licensing arrangements in cost-reducing cumulative innovation. There exists the following results. First, for the first-generation patentee, ex post licensing matters for rent extraction while ex ante licensing matters for efficiency. Second, if the second-generation innovator does not exit, then the firms’ profits as well as social welfare are all irrelevant to whether ex ante licensing is allowed. Third, costly litigation can occur on the equilibrium path and its occurrence is also irrelevant to ex ante licensing. Interestingly, the conditional probability of the first-generation patentee winning litigation first decreases and then increases in patent breadth. Fourth, optimal patent breadth depends on the tradeoff between litigation costs and antitrust effect. Translated from Shijie Jingji Wenhui 世界经济文汇 (World Economic Papers), 2006, (6): 1–29     

Risk sharing and industrial specialization in China

We investigate how risk sharing shapes industrial specialization across prefecture-level cities in China. By unbundling the mechanisms of risk sharing, we find that ex ante risk sharing generates a first-order stimulant effect on the geographical concentration of manufacturing industries, particularly for non-state-owned enterprises and cyclical industries. Ex post risk sharing matters only for state-owned enterprises. This result remains robust to instrument variable estimation and controlling for other determinants of industrial specialization. Finally, we show that interregional labor migration (special fiscal transfers) plays an important role in promoting interregional ex ante (ex post) risk sharing. The study implies that much more risk sharing and efficiency gains from industrial specialization would be achieved if capital markets and credit markets are better developed.     

Growth with many agents and wages paid ex ante

In this paper, we consider a one-sector model of economic growth with several infinitely-lived heterogeneous agents, who are endowed with diverse discount factors as well as preferences over consumption. In line with the classical Ramsey model, agents are not allowed to borrow against future income. Unlike the traditional assumption of ex post wage payment, wages are paid ex ante in our model. We first explain the difference between the assumptions of wages being paid ex ante and wages being paid ex post in the framework of a simple illustrative two-class model. Our main result shows that in contrast to the many-agent Ramsey model with ex post wage payment, the capital stock sequence converges to the steady state stock irrespective of production technology employed by the firms. Further, all impatient agents own zero capital stock, whereas the most patient agent owns the entire capital stock from some time onward. Thus, we have shown that a slight modification in the timing of wage payment in growth models can lead to significant changes in the stability properties of equilibrium dynamics.     

Monopoly Price Dispersion Under Demand Uncertainty

When a monopolist sets its price before its demand is known, then it may set more than one price and limit the availability of its output at lower prices. This article adds demand uncertainty and price rigidities to the standard model of monopoly pricing. When there are two states of demand and the ex post monopoly price is greater when demand is high then the monopolist's optimal ex ante pricing strategy is to set two prices and limit purchases at the lower price.     

Rational Speculative Bubbles: An Empirical Investigation of the London Stock Exchange

In recent years, a sharp divergence of London Stock Exchange equity prices from dividends has been noted. In this paper, we examine whether this divergence can be explained by reference to the existence of a speculative bubble. Three different empirical methodologies are used: variance bounds tests, bubble specification tests, and cointegration tests based on both ex post and ex ante data. We find that, stock prices diverged significantly from their fundamental values during the late 1990's, and that this divergence has all the characteristics of a bubble.     

Ex Post Welfare under Alternative Health Care Systems

The implications of a societal aversion to inequality for the optimal structure of the health care system are studied. The agents are assumed to be ex ante identical, but to differ ex post in the state of their health. Inequality aversion is introduced by postulating a strictly concave ex post social welfare function. It is shown that the optimal public health care system allocates health care differently than would private health insurance; specifically, people who are relatively unhealthy with and without treatment receive more health care, and people who are relatively healthy with and without treatment receive less health care. The aggregate quantity of health care under the optimal public health care system can be either greater or smaller than under private health care insurance. If the public health care system is optimally designed, allowing agents to purchase supplementary private health care insurance cannot raise social welfare and is likely to decrease it.     

Barriers to Global Free Trade through Bilateral Agreements

This paper examines the formation of bilateral free trade agreements (FTAs) in the context of a dynamic noncooperative bargaining game with a random proposer. We show that global free trade (a grand coalition) does not necessarily occur unless transfer payments among countries are allowed. When transfer payments are possible, bilateral FTAs always achieve global free trade, but the ex‐ante and ex‐post inequalities of social welfare among countries are larger than those when all countries are independent because of the strategic bargaining behavior.     

REALIZED COST‐BASED SUBSIDIES FOR STRATEGIC R&D INVESTMENTS WITH EX ANTE AND EX POST ASYMMETRIES*

We discuss stochastic cost‐reducing R&D investments and examine efficient subsidies. We discuss a two‐stage duopoly model in which each firm chooses R&D levels (innovation size and probability of success) in the first stage and competes à la Cournot in the second stage. We find that simple subsidies depending on the realized cost differences induce the efficient levels of R&D with respect to the innovation size and probability of success by two firms regardless of ex ante and ex post asymmetries between the two firms.     

An empirical investigation into the impact of US federal government budget deficits on the real interest rate yield on intermediate-term treasury issues, 1972–2012

This study provides new empirical evidence on the impact of the federal budget deficit on the real interest rate yields on intermediate-term debt issues of the US Treasury, represented herein by the ex post real interest rate yields on 3-year Treasury notes and 7-year Treasury notes, two interest rate measures that have received essentially no attention in the economics and finance literature in recent years. This study is couched within a loanable funds model that includes two ex post real interest rate yields, the monetary base as a per cent of GDP, the change in per capita real GDP, net financial capital inflows as a per cent of GDP and the budget deficit as a per cent of GDP. This study uses annual data for the study period 1972 to 2012, a time period that includes ‘quantitative easing’ monetary policies by the Federal Reserve. Two-stage least squares estimations reveal that the federal budget deficit, expressed as a per cent of GDP, exercised a positive and statistically significant impact on the ex post real interest rate yields on both 3-year and 7-year Treasury notes, even after allowing for quantitative easing and other factors. The study also considers the time period 1980 to 2012 and offers simple robustness testing.     

Comparing Environmental Policy Instruments Within an Incomplete Contract Framework

This paper compares three different legal means—no environmental policy (the pollutee pays), full liability (the polluter pays), and pollution standards—to reduce and regulate neighborhood externalities within an incomplete contract framework. It turns out that the relative efficiency of these instruments depends, in general, on details. However, moderate standards are preferable to no environmental policy and tight (but not too tight) standards dominate liability. This provides under the given assumptions (neighborhood externalities, incomplete contracts) a justification for “sensible” standards for three reasons. First, unilateral allocations of property rights are biased that distort allocations even if ex post bargaining takes place. Second, a standard is superior in the following sense: if it is set equal to the outcome under any allocation of rights, it will be improved in the process of ex post bargaining. Third, unilateral property rights encourage strategic ex ante investments up to the point that committing to no bargaining would be beneficial (if possible).