Testing scale efficiency in DEA models: a bootstrapping approach

This paper presents a method for estimation and test of firm-specific scale efficiency using data envelopment analysis (DEA). The use of a simple bootstrap algorithm is proposed to perform firm-specific inference for scale efficiency. An empirical application using Swedish hospital data is provided. It is found that about 40% of the departments were scale efficient according to the original results. However, for about one-third of those departments the hypothesis of scale efficiency could be rejected.     

REGIONAL VARIATION IN LIVELIHOOD STRATEGIES IN MALAWI

We identified livelihood strategies at the household level as a function of assets held using survey data from Malawi. We only included endowments that we expected to be predetermined. As expected, land, household size, age and primary education are important determinants of livelihood strategies. It also turned out to be significant regional variation in livelihood strategies, with more diversification in the southern region, and with regional variation in the role of ethnic and religious identity as determinants of livelihood strategies. In particular, we found that households from the Chewa community have more livelihood opportunities in the south, where they are in a minority.     

WAGE DETERMINATION UNDER NON-LINEAR TAXES: ESTIMATION AND AN APPLICATION TO PANEL DATA

This paper studies wage determination under piecewise lineartaxes in a unionised labour market. The purposes of the paperare to model how piecewise linear taxation affects the choiceset of the union, and to take this information into accountin the estimation. The empirical application is based on paneldata. Piecewise linear taxes necessitates formal assumptionsabout the sources of randomness, and we find that both unobservedheterogeneity and measurement errors in the wage rate are importantto consider in the estimation. We also find that taxes are likelyto have a non-negligible impact on the (pre-tax) wage rate.     

Immigrant–Native Differences in Welfare Participation: The Role of Entry and Exit Rates

We analyze differences in welfare transitions between natives and immigrants in Sweden using a large representative panel data set. The data contain administrative information on welfare use and detailed demographic information. The empirical results suggest that the main reason for the large immigrant–native welfare gap observed is the differences in welfare entry rates. Thus, policies aimed to reduce these transitions may be particularly successful in reducing welfare use in general and particularly the immigrant–native welfare gap.     

Price and Investment Dynamics: Theory and Plant-Level Data

We construct a model of a firm competing for market share in a customer market and making investments in physical capital. The firm is financially constrained and there are implementation lags in investment. Our model predicts that product prices should depend on costs and competitors' prices but respond weakly to demand shocks. Also, prices should be strongly related to investment. We estimate price and investment equations on panel data for Swedish manufacturing plants and find results that are qualitatively in line with these predictions, though the relation between investment and prices is stronger than predicted by our model.     

Genetic Variation in Financial Decision‐Making

Individuals differ in how they construct their investment portfolios, yet empirical models of portfolio risk typically account only for a small portion of the cross‐sectional variance. This paper asks whether genetic variation can explain some of these individual differences. Following a major pension reform Swedish adults had to form a portfolio from a large menu of funds. We match data on these investment decisions with the Swedish Twin Registry and find that approximately 25% of individual variation in portfolio risk is due to genetic variation. We also find that these results extend to several other aspects of financial decision‐making.     

On the Asset Allocation of a Default Pension Fund

We characterize the optimal default fund in a defined contribution (DC) pension plan. Using detailed data on individuals' holdings inside and outside the pension system, we find substantial heterogeneity within and between passive and active investors in terms of labor income, financial wealth, and stock market participation. We build a life‐cycle consumption‐savings model, with a DC pension account and an opt‐out/default choice, that produces realistic investor heterogeneity. Relative to a common age‐based allocation, implementing the optimal default asset allocation implies a welfare gain of 1.5% during retirement. Much of the gain is attainable with a simple rule of thumb.     

THE ROLE OF MODEL SPECIFICATION IN FINDING THE INFLUENCE OF OWNERSHIP AND REGULATORY REGIME ON UTILITY COST: THE CASE OF SWEDISH ELECTRICITY DISTRIBUTION

The lack of consensus on how utility cost is affected by variation in ownership and regulatory regime has been attributed to sector‐specific conditions and interacting observed heterogeneous factors. This study investigates a further source of ambiguous outcomes as it evaluates different econometric specifications related to variations in utility objective/the design of regulatory regime and influences from unknown/uncertain heterogeneous factors. Consistent with theoretical predictions, 7 years of data from the Swedish electricity distribution sector reveal that private ownership and stronger financial incentives are associated with lower costs. It is also demonstrated that inappropriate model specifications can produce arbitrary conclusions. (JEL D24, K23, L51, L94)     

Pricing Currency Risks

The currency market features a small cross-section, and conditional expected returns can be characterized by few signals: interest differential, trend, and mean reversion. We exploit these properties to construct the ex ante mean-variance efficient portfolio of individual currencies. The portfolio is updated in real time and prices all prominent currency trading strategies, conditionally and unconditionally. The fraction of risk in these assets that does not affect their risk premiums is at least 85%. Extant explanations of carry strategies based on intermediary capital or global volatility are related to these unpriced components, while consumption growth is related to the priced component of returns.