J.C. Siebrand – författare

This volume has been composed to commemorate the day, 25 years ago, that Dr. P. J. Verdoorn delivered his inaugural lecture after his appointment as professor of economics at the Netherlands School of Economics at Rotterdam. The prompt and enthusiastic reactions by several members of the profession on our request for a contribution illustrates the fact that Verdoorn is held in high esteem by those who worked with him and those who are acquainted with his work. We thank all the contributors for having helped us to realize our plan to honour Verdoorn with the publication of this ''liber amicorum''. Verdoorn was appointed part time professor of business statistics, market research and marketing in 1952. He held this post until 1969. In that year he started lectures closer related to his work as deputy director of the Central Planning Bureau: general economic research. He became full professor of macro-economic policy in 1975. Verdoorn showed a great versatility in all the fields on which he worked. Without exaggeration he may be characterised as one of the most many-sided economists in the Nether­ lands. However much the subjects he studied may have varied, the methods he applied show persistent characteristics: theories are formulated to yield testable hypotheses which, when they can be maintained, are made operatio­ nal for policy purposes. In all these phases of a research program Verdoorn showed a high level of inventivity. A combination of rigour and imagination enabled him to maintain a constant stream of high-quality publications.

This volume has been composed to commemorate the day, 25 years ago, that Dr. P. J. Verdoorn delivered his inaugural lecture after his appointment as professor of economics at the Netherlands School of Economics at Rotterdam. The prompt and enthusiastic reactions by several members of the profession on our request for a contribution illustrates the fact that Verdoorn is held in high esteem by those who worked with him and those who are acquainted with his work. We thank all the contributors for having helped us to realize our plan to honour Verdoorn with the publication of this 'liber amicorum'. Verdoorn was appointed part time professor of business statistics, market research and marketing in 1952. He held this post until 1969. In that year he started lectures closer related to his work as deputy director of the Central Planning Bureau: general economic research. He became full professor of macro-economic policy in 1975. Verdoorn showed a great versatility in all the fields on which he worked. Without exaggeration he may be characterised as one of the most many-sided economists in the Nether­ lands. However much the subjects he studied may have varied, the methods he applied show persistent characteristics: theories are formulated to yield testable hypotheses which, when they can be maintained, are made operatio­ nal for policy purposes. In all these phases of a research program Verdoorn showed a high level of inventivity. A combination of rigour and imagination enabled him to maintain a constant stream of high-quality publications.

This volume has been composed to commemorate the day, 25 years ago, that Dr. P. J. Verdoorn delivered his inaugural lecture after his appointment as professor of economics at the Netherlands School of Economics at Rotterdam. The prompt and enthusiastic reactions by several members of the profession on our request for a contribution illustrates the fact that Verdoorn is held in high esteem by those who worked with him and those who are acquainted with his work. We thank all the contributors for having helped us to realize our plan to honour Verdoorn with the publication of this 'liber amicorum'. Verdoorn was appointed part time professor of business statistics, market research and marketing in 1952. He held this post until 1969. In that year he started lectures closer related to his work as deputy director of the Central Planning Bureau: general economic research. He became full professor of macro-economic policy in 1975. Verdoorn showed a great versatility in all the fields on which he worked. Without exaggeration he may be characterised as one of the most many-sided economists in the Nether­ lands. However much the subjects he studied may have varied, the methods he applied show persistent characteristics: theories are formulated to yield testable hypotheses which, when they can be maintained, are made operatio­ nal for policy purposes. In all these phases of a research program Verdoorn showed a high level of inventivity. A combination of rigour and imagination enabled him to maintain a constant stream of high-quality publications.

Most re cent contributions to disequilibrium theory have a high level of abstraction. Empirical studies explicitly based on disequilibrium are still relatively scarce. However, empirical macro economics anticipated the theoretical development, and amalgamated classical and Keynesian elements often without a clear-cut formal base. Now a theoretical integration of neo-classical and neo-Keynesian economics seems under way. There is a renewed interest in the micro-economic foundations of macroeconomics with a special focus on the behaviour of economic agents operating in non-clearing markets. In some instances these theoretical developments offer an ex post justification for empirical macro-economic practices. Generally however, they call for new ways of empirical macro-economic model building. This study operates on the border line between empirical macro economics and theoretical disequilibrium macro-economic theory. Our interest in macro-economic disequilibrium originates from the empirical side. Foreign trade relations for several countries revealed significant pressure of demand effects. Hence, the spillover of excess demand in domestic markets to foreign markets seemed a rather general phenomenon. This fact could be explained by a theory that states that actual demand for products from domestic ftrms will gene rally and systematically differ from the ex ante demand as suggested by equilibrium analysis. This latter demand concept comes close to Clower's 'notional demand' and Patinkin's 'potential demand'.