Organisatie en financiering van de Nederlandse gezondheidszorg

Bespreking van D. Dolman, Subsidies en gezondheidszorg, een feitelijk onderzoek naar financieringsstructuren, ac. proefschrift, Universiteit van Amsterdam 1964, H. E. Stenfert Kroese N.V., Leiden, 240 blz.     

The Marshallian Market and the Walrasian Economy. Two Incompatible Bedfellows

The aim of this paper is to question a view which is usually taken for granted, namely that the Marshallian partial equilibrium and Walrasian general equilibrium analysis stand in a relationship of continuity. It will be claimed that the contrary is true: the generalisation of the Marshallian market does not lead to a Walrasian economy or, conversely, the Walrasian economy is not composed of Marshallian markets. To bring this point home, the basic methodological choices underpinning the analysis of the Marshallian market and of the Walrasian economy will be compared. The issue of why no full-fledged Marshallian representation of the economy has arisen which might stand as an alternative to the Walrasian account will also be investigated and a series of reasons for this lack of generalisation of the Marshallian market will be considered. Finally, it will be claimed that if the Marshallian economy concept has no explicit existence, it has nonetheless an implicit one. It forms the background against which a series of reasoning about the working of the economy as a whole, which cannot fit the Walrasian economy framework, are developed. No less prestigious names than those of Keynes, Hicks, Patinkin, Friedman, Clower and Leijonhufvud will be adduced as witnesses.     

A Jump-diffusion Model for Exchange Rates in a Target Zone

We propose a simple jump-diffusion model for an exchange rate target zone. The model captures most stylized facts from the existing target zone models while remaining analytically tractable. The model is based on a modified two-limit version of the C OX , I NGERSOLL and R OSS (1985) model. In the model the exchange rate is kept within the band because the variance decreases as the exchange rate approaches the upper or lower limits of the band. We also consider an extension of the model with parity adjustments, which are modeled as Poisson jumps. Estimation of the model is by GMM based on conditional moments. We derive prices of currency options in our model, assuming that realignment jump risk is idiosyncratic. Throughout, we apply the theory to EMS exchange rate data. We show that, after the EMS crisis of 1993, currencies remain in an implicit target zone which is narrower than the officially announced target zones.     

Hayek and Keynes: From a common critique of economic method to different theories of expectations

The methodological positions of Hayek and Keynes contain striking similarities. Both authors opposed empiricist approaches to economics that assign priority to mere observation as the source of knowledge. Both emphasised intentionality, motivation and human agency. Notwithstanding this common ground, they had different conceptions of how beliefs are formed and had different explanations of thought and action in economics. Hayek grounded his explanation on an evolutionary theory of the mind, i.e. on psychological premises, whereas Keynes based his view of belief formation on probable reasoning, where probability is a logical concept. Starting from psychological premises Hayek maintained that individuals act rationally only by following rules. As a consequence, he considered conventional expectations to be the primary guide for agents in economic life. Keynes agreed that conventional expectations actually guide economic behaviour, but he maintained that they are justified only in situations of total ignorance. In conditions of limited knowledge, agents can base their action on reasonable expectations, independently of conventions. Moreover, agents?particularly those institutions responsible for economic policy?ought to shun conventional behaviour in order to counteract its negative social consequences. We argue that Keynes's theory of expectations is well grounded upon his theory of logical probability. Hence his advocacy of discretionary policy is rationally justified.     

Market illiquidity and bounds on European option prices

The paper analyses the impact of illiquidity of a stock paying no dividends on the pricing of European options written on that stock. In particular, it is shown how illiquidity generates price bounds on an option on this stock, even in the absence of other imperfections, such as transaction costs and trading constraints, or the assumption of stochastic volatility. Moreover, price bounds are shown to be asymmetric with respect to the option price under perfect liquidity. This fact explains, under some conditions, the appearance of a smile effect when the implied volatility is estimated from the mid-quote.     

On the Role of Outsiders in Technical Development

In this paper, it is argued that outsiders play an important role in the dynamics of technical change and that, for this reason, outsider involvement is also an important entry if one wants to 'improve' or democratize technical development. Outsiders are defined as people not involved in technical development and not sharing the rules that guide the design and development of a technology. The totality of these rules makes up the technological regime of a technology. Technological regimes are characterized by certain trajectories of technical development. The focus in this paper is on outsiders who may trigger (radical) technical change that transform current technological regimes. Three different types of such outsiders are distinguished and their role in technical development is discussed: professional scientists and engineers, outsider firms and societal pressure groups.