Residential radon-222 exposure and lung cancer: exposure assessment methodology

Although occupational epidemiological studies and animal experimentation provide strong evidence that radon-222 (222Rn) progeny exposure causes lung cancer, residential epidemiological studies have not confirmed this association. Past residential epidemiological studies have yielded contradictory findings. Exposure misclassification has seriously compromised the ability of these studies to detect whether an association exists between 222Rn exposure and lung cancer. Misclassification of 222Rn exposure has arisen primarily from: 1) detector measurement error; 2) failure to consider temporal and spatial 222Rn variations within a home; 3) missing data from previously occupied homes that currently are inaccessible; 4) failure to link 222Rn concentrations with subject mobility; and 5) measuring 222Rn gas concentration as a surrogate for 222Rn progeny exposure. This paper examines these methodological dosimetry problems and addresses how we are accounting for them in an ongoing, population-based, case-control study of 222Rn and lung cancer in Iowa

Evidence synthesis as the basis for decision analysis: a method of selecting the best agricultural practices for multiple ecosystem services

Agricultural management practices have impacts not only on crops and livestock, but also on soil, water, wildlife, and ecosystem services. Agricultural research provides evidence about these impacts, but it is unclear how this evidence should be used to make decisions. Two methods are widely used in decision making: evidence synthesis and decision analysis. However, a system of evidence-based decision making that integrates these two methods has not yet been established. Moreover, the standard methods of evidence synthesis have a narrow focus (e.g., the effects of one management practice), but the standard methods of decision analysis have a wide focus (e.g., the comparative effectiveness of multiple management practices). Thus, there is a mismatch between the outputs from evidence synthesis and the inputs that are needed for decision analysis. We show how evidence for a wide range of agricultural practices can be reviewed and summarized simultaneously (“subject-wide evidence synthesis”), and how this evidence can be assessed by experts and used for decision making (“multiple-criteria decision analysis”). We show how these methods could be used by The Nature Conservancy (TNC) in California to select the best management practices for multiple ecosystem services in Mediterranean-type farmland and rangeland, based on a subject-wide evidence synthesis that was published by Conservation Evidence (www.conservationevidence.com). This method of “evidence-based decision analysis” could be used at different scales, from the local scale (farmers deciding which practices to adopt) to the national or international scale (policy makers deciding which practices to support through agricultural subsidies or other payments for ecosystem services). We discuss the strengths and weaknesses of this method, and we suggest some general principles for improving evidence synthesis as the basis for multi-criteria decision analysis

The Market Pricing of Special Items that are Included in versus Excluded from Street Earnings

We re-investigate the market pricing of special items, with particular emphasis on how managers " frame " these non-operating earnings components via their inclusion or exclusion from " street " earnings, the earnings numbers that firms disclose in their press releases and that analysts track and forecast. When managers include the special items in " street earnings (i.e., " street " = GAAP), the market overprices them, believing the special items to be more persistent than they actually are. As a result, there is a negative relationship between the special items and future stock returns in the following year. However, when managers exclude special items from " street " earnings (i.e., " street " not equal GAAP), the market recognizes their transitory characteristic and the relationship between special items and returns is insignificant in the following year. We also demonstrate that the decision to include (exclude) special items with (from) " street " earnings is associated with whether inclusion or exclusion of special items a) increases earnings numbers, b) smoothes the earnings series, or c) helps managers to meet earnings benchmarks. These results suggest that the decision to include or exclude special items from " street " earnings is associated with managerial incentives to manage earnings numbers rather than signal the persistence of special items

Consistency in meeting or beating earnings expectations and management earnings forecasts

This paper provides evidence that firms that have consistently met or beaten analysts' earnings expectations (MBE) provide more frequent "bad news" management forecasts than firms with no established string of MBE, particularly when existing analyst forecasts are optimistic. This suggests that firms with a consistent MBE record are more likely to guide analysts' expectations downward to avoid breaking the consistency. Subsequent analyst forecast revisions following bad news management forecasts issued by these firms are dampened, implying that analysts suspect that these forecasts may be opportunistic. The relation between management forecasts and MBE consistency is stronger after Regulation FD.Consistency in meeting and beating earnings expectations Management forecast disclosure Forecast bias Analyst forecast revision Regulation Fair Disclosure

Quarterly Earnings Announcements and Market Risk Adjustments

We examine (1) whether there is a shift in beta for "individual" securities around quarterly earnings announcements, and (2) whether these beta changes relate to certain characteristics of the firms. We find a statistically significant upward (downward) beta shift during the two-day earnings announcement period for 25 per cent (9 per cent) of a sample of 195 US firms. We also find that the beta shift at the time of the earnings announcement is significantly higher for small firms (i.e., more precise announcements). Copyright Blackwell Publishers Ltd 1999.