The Impact of the Inpatient Prospective Payment System and Diagnosis-Related Groups

Abstract

The outpatient prospective payment system for the Medicare program became effective Aug. 1, 2000, as mandated by the Balanced Budget Act of 1997. This outpatient program complements Medicare’s inpatient prospective payment system, which was introduced in 1983. A survey of the literature over the past 20 years is undertaken to review the effects of the inpatient prospective payment system and diagnosis-related groups (DRGs) on inpatient hospital utilization, expenditures, and outcomes. The level of the DRG payment has been questioned, as well as the process of adjusting the payment levels from one year to the next. In addition, past research has speculated that the DRG classification may not be sensitive to severity and is subject to coding ambiguities. These conclusions can be used as input to future research on the new outpatient program, as well as updating research on the inpatient program.     

Distortion Risk Measures and Economic Capital

Abstract

To provide incentive for active risk management, it is argued that a sound coherent distortion risk measure should preserve some higher degree stop-loss orders, at least the degree-three convex order. Such risk measures are called tail-preserving risk measures. It is shown that, under some common axioms and other plausible conditions, a tail-preserving coherent distortion risk measure identifies necessarily with the Wang right-tail measure or the expected value measure. This main result is applied to derive an optimal economic capital formula.     

Market-Consistent Valuation and Funding of Cash Balance Pensions

Cash balance pension benefits are accumulated at guaranteed crediting rates, usually based on yields on government securities. Viewed as a financial liability, the benefit is a form of interest rate derivative, which can be valued using financial models and theory. In this article, we derive the market value for a range of commonly used crediting rates, assuming the accrued benefit liability comprises the past contributions, allowing for full interest credits up to a known future retirement date. We use the Hull-White interest rate model to determine crediting rates and to determine the market value. We explore the risks associated with different crediting rate choices by evaluating the liability using market data from 1998 to 2013. We propose two other approaches to the accrued benefit. The first approach assumes the accrued benefit comprises past contributions with interest up to the valuation date, but no future interest credits. Future credits on past contributions are assumed funded through future contributions. The second method projects all contributions and interest to retirement and assumes equal units of accrual of this projected benefit in each year of service. We compare the three approaches through numerical examples.     

Time varying country risk: an assessment of alternative modelling techniques

Three different techniques for the estimation of a time-varying beta are investigated: a bivariate GARCH model, the Schwert and Seguin approach, and the Kalman filter method. These approaches are applied to a set of monthly Morgan Stanley country index data over the period 1970 to 1995 and their relative performances compared. In-sample forecast tests of the performance of each of these methods for generating conditional beta suggest that the GARCH-based estimates of risk generate the lowest forecast error although these are not necessarily significantly less than those generated by the other techniques considered.     

The Demise of Investment Banking Partnerships: Theory and Evidence

In 1970 the New York Stock Exchange relaxed rules that prohibited the public incorporation of member firms. Investment banking concerns went public in waves, with Goldman Sachs the last of the bulge bracket banks to float. We explain the pattern of investment bank flotations. We argue that partnerships foster the formation of human capital and we use technological advances that undermine the role of human capital to explain the partnership's going‐public decision. We support our theory using a new data set of investment bank partnership statistics.     

Benchmarking benchmarks: measuring characteristic selectivity using portfolio holdings data

This study proposes methodological adjustments to the widely adopted performance benchmarking methodology of Daniel et al. (1997 ) as a means of improving the precision of alpha measurement for active equity fund managers. We achieve this by considering the monthly updating of characteristic benchmarks and to ensure neutrality to the Standard & Poor's/Australian Stock Exchange 300 index. Applying this benchmark to a representative sample of active Australian equity funds and simulated passive portfolios that mimic fund manager‐style characteristics, we find statistically different and lower tracking error compared with using the standard characteristic benchmark methodology. We also find evidence that the modified benchmark statistically infers an alpha closer to zero compared with the standard benchmark methodology. Our findings suggest that improved specifications of characteristic benchmarks represent better methods in quantifying fund manager skill.     

Capitalizing on Catastrophe: Short Selling Insurance Stocks Around Hurricanes Katrina and Rita

We develop several hypotheses regarding short‐selling activity around Hurricanes Katrina and Rita. We find that abnormal short selling does not increase until 2 trading days after the landfall of Katrina and that short‐selling activity is much more significant around Rita. We find a substantial increase in short‐selling activity in the trading days prior to the landfall of Rita and relatively less short‐selling activity in the trading days after landfall. There is little evidence that suggests that traders short insurance stocks with more potential exposure in the Gulf region than other insurance stocks in the days before landfall.     

International evidence on fiscal solvency: Is fiscal policy “responsible”?

We conduct a cross-country empirical analysis of fiscal solvency based on dynamic stochastic general equilibrium conditions. The results show evidence of fiscal solvency, in the form of a robust positive conditional response of the primary balance to changes in public debt, in panels for emerging and industrial economies and in a combined panel. Emerging economies show a stronger response and hence converge to lower mean debt-output ratios, as observed in the data. The results are weaker for countries with debt ratios exceeding panel means and medians. Hence, we can separate countries where fiscal solvency holds from those where it remains in doubt.