Testing for Unit Roots with Breaks: Evidence on the Great Crash and the Unit Root Hypothesis Reconsidered

Nelson and Plosser (1982), in a classic paper, failed to find strong evidence against the null hypothesis of a generating process with a unit autoregressive root for thirteen US macroeconomic time series. Perron (1989) claimed that such evidence was available for a majority of these series if the alternative hypothesis was of trend stationarity with a break in 1929. Zivot and Andrews (1992) treated the break date as endogenous, then finding strong evidence agcainst the null for a minority of these series. Our own analysis extends theirs by permitting a break under the null as well as the alternative hypothesis, and allowing for the sequential nature of the testing. Our empirical findings complete the circle. We find no strong evidence against the unit root hypothesis for any of the thirteen Nelson–Plosser series.     

OPTIONS AND EFFICIENCY IN MULTIDATE SECURITY MARKETS

This paper extends the work of Ross (1976; Q. J. Econ. (90)1, 75–89) to multidate security markets. First, we show that if a primitive security separates states at the terminal date, then there exist multiperiod European options on that security generating dynamically complete markets. Second, we show that if a primitive security conditionally separates states at the terminal date, then there exist multiperiod European options on that security generating generically dynamically complete markets provided that certain conditions hold. Third, we show that there are economies for which the minimum number of multiperiod European options on a primitive security generating generically dynamically complete markets is relatively large. Finally, we show that in these economies, a relatively small number of multiperiod European options on possibly different portfolio strategies of primitive securities generates generically dynamically complete markets.     

Small dimension PDE for discrete Asian options

This paper presents an efficient method for pricing discrete Asian options in presence of smile and non-proportional dividends. Using an homogeneity property, we show how to reduce an n0 dimensional problem to a one- or two-dimensional one. We examine different numerical specifications of our dimension reduced PDE using a Crank–Nicholson method (interpolation method, grid boundaries, time and space steps) as well as the extension to the case of non-proportional discrete dividends, using a jump condition. We benchmark our results with Quasi Monte-Carlo simulation and a multi-dimensional PDE     

Modeling Distribution Services and Assessing Their Welfare Effects in a General Equilibrium Framework

Most international trade models fail to account for the fact that almost all goods must pass through the distribution sector. The authors compare different approaches to modeling distribution within an Applied General Equilibrium framework and find that such modeling may significantly affect trade opening simulations. They also predict large potential gains from streamlining distribution. For instance, a 10% reduction in Japan's final goods distribution margins would benefit it as much as worldwide free trade would. They also find that, compared to trade opening, reducing margins leads to smaller inter‐sectoral production shifts and thus may engender less political opposition.     

On the Non-Existence of Redundant Options

In a seminal paper, Ross (Q J Econ 90:75–89, 1976) shows that if security markets are resolving, then there exist (non-redundant) options that generate complete security markets. Complementing his work, Aliprantis and Tourky (2002) show that if security markets are strongly resolving and the number of primitive securities is less than half the number of states, then every option is non-redundant. Our paper extends Aliprantis and Tourky’s result to the case when their condition on the number of primitive securities is not imposed. Specifically, we show that if there exists no binary payoff vector in the asset span, then for each portfolio there exists a set of exercise prices of full measure such that any option on the portfolio with an exercise price in this set is non-redundant. Since the condition that there exists no binary payoff vector in the asset span holds generically, redundant options are thus rare. I am grateful to an anonymous referee for very helpful comments. Research support from the School of Business at The George Washington University is gratefully acknowledged     

Should business groups be dismantled? The equilibrium costs of efficient internal capital markets

We analyze the relationship between conglomerates’ internal capital markets and the efficiency of economy-wide capital allocation, and we identify a novel cost of conglomeration that arises from an equilibrium framework. Because of financial market imperfections engendered by imperfect investor protection, conglomerates that engage in winner-picking (Stein, 1997 [Internal capital markets and the competition for corporate resources. Journal of Finance 52, 111–133]) find it optimal to allocate scarce capital internally to mediocre projects, even when other firms in the economy have higher-productivity projects that are in need of additional capital. This bias for internal capital allocation can decrease allocative efficiency even when conglomerates have efficient internal capital markets, because a substantial presence of conglomerates might make it harder for other firms in the economy to raise capital. We also argue that the negative externality associated with conglomeration is particularly costly for countries that are at intermediary levels of financial development. In such countries, a high degree of conglomeration, generated, for example, by the control of the corporate sector by family business groups, could decrease the efficiency of the capital market. Our theory generates novel empirical predictions that cannot be derived in models that ignore the equilibrium effects of conglomerates. These predictions are consistent with anecdotal evidence that the presence of business groups in developing countries inhibits the growth of new independent firms because of a lack of finance.     

Does the Basle Capital Accord reduce bank fragility? An assessment of the value-at-risk approach

We examine the economic implications arising from a bank using a VaR-constrained mean-variance model for the selection of its trading portfolio as a consequence of the Basle Capital Accord. Surprisingly, we show that when a VaR constraint is imposed, it is plausible that certain banks will end up selecting ‘riskier’ portfolios than they would have chosen in the absence of the constraint. Accordingly, regulators such as the Basle Committee on Banking Supervision should be aware that allowing a bank to use VaR to determine its minimum regulatory capital may increase its fragility. Alternatives to VaR-based bank capital regulation that mitigate or even preclude its perverse implications are presented.     

Analysing enterprise architecture maturity models: a learning perspective

In order to aid organisations in the adoption of enterprise architecture (EA) best practices, maturity models have been proposed in the literature. These models offer organisational roadmaps and assessment frameworks for increasing EA maturity. However, key questions concerning the implied meaning of the term maturity in the context of these models have been left unexplored by previous research. This research, aided by the field of organisational learning, offers new insights into the implied assumptions of current EA maturity models and offers initial concepts and constructs to guide the conceptualisation, construction and refinement of enterprise maturity models.     

Valuation of forward start options under affine jump-diffusion models

Under the general affine jump-diffusion framework of Duffie et al. [Econometrica, 2000, 68, 1343–1376], this paper proposes an alternative pricing methodology for European-style forward start options that does not require any parallel optimization routine to ensure square integrability. Therefore, the proposed methodology is shown to possess a better accuracy–efficiency trade-off than the usual and more general approach initiated by Hong [Forward Smile and Derivative Pricing. Working paper, UBS, 2004] that is based on the knowledge of the forward characteristic function. Explicit pricing solutions are also offered under the nested jump-diffusion setting proposed by Bakshi et al. [J. Finance, 1997, 52, 2003–2049], which accommodates stochastic volatility and stochastic interest rates, and different integration schemes are numerically tested.     

Myopic market pricing and managerial myopia

This paper develops a firm‐level measure of myopic market pricing, which captures the extent to which the market overvalues short‐term expected abnormal earnings relative to longer‐term ones. The empirical analysis shows that myopically priced firms manage earnings more actively and invest less in R&D. The impact of myopic market pricing is concentrated in firms where managers cater more to market pricing, that is, in firms with greater short‐term investor ownership, with CEO compensation that is more sensitive to the firm share price, and with higher equity dependence. Additional tests show that these findings are robust to the consideration of market (under)overpricing. The results suggest that when managers cater to market pricing, market myopia encourages managerial myopia.