Rolf dedicated entirely to his scientific work, and he managed to maintain an excellent relationship with his colleague and wife Any, and thereafter with his son Pablo and fiancée. In addition to that, he had an extraordinary bias toward argentine economists, spending all of his time to make comments, give help and support to the development of economic departments throughout Latin America. The impact of his personality had reflected on his funeral at the British cemetery in Buenos Aires, where a great deal of argentine economists and his most recent students were present. It is as if, by having a quick burial without a wake - his own wish - Rolf would express his desire of gathering all of us to bear him farewell.

Rolf's interest for economics awakened in the advanced seminars directed by Professor Julio H. G. Olivera at the Faculty of Economic Sciences of the University of Buenos Aires. There, he was part of a group with Any Martirena, Guillermo Calvo, Héctor Diéguez, Arturo O'Connell, Morris Teubal among others. He then got his Ph D at the University of Yale in New Haven, United States. Any, Guillermo Calvo, Elías Salama and Jorge Sakamoto were also there. His teachers at Yale were Tjalling Koopmans, Herbert Scarf, Marc Nerlove, James Tobin. Returning to Argentina, he entered the new Torcuato Di Tella Institute, and kept tight contact with Miguel Sidrauski and Morris Teubal, who were already active from Chicago.

In Argentina Rolf had an active participation in the development of centres of research and departments of economics in several universities. In the Centre of Economic Research at the Di Tella Institute he integrated the group of what we could call the first generation, among whom were Guido Di Tella, Javier Villanueva, Adolfo Canitrot, Mario Brodersohn, Alieto Guadagni, José M. Dagnino Pastore, Héctor Diéguez, Eduardo Zalduendo, Felipe Tami, Federico Herschel, Julio Berlinski, Alberto Petrecolla, Jorge Sakamoto and Any. At the same time he was teaching economics at the Argentine Catholic University, where he had helped shape many fellow students.

He was then attracted to the Centre for Macroeconomic Research of Argentina (CEMA) created by Pedro Pou. There he analyzed economic issues with Carlos Rodríguez, Roque Fernández, Osvaldo Schenone, Víctor Yohai and Pedro. He was a professor at the Faculty of Economic Sciences of the University of Buenos Aires in several opportunities. In the end he was "acquired" by the University of San Andrés, where as Director of the Departments of Economics and Mathematics he had a strong leadership and attracted such people as Roberto Cortés Conde, Osvaldo Schenone, George MacCandless, Victor Yohai, Mariano Tommasi and others, including several economists teaching in various fields. There he stimulated the creation of a postgraduate program after bringing to a prestigious level the Degree in Economics. He entered the National Academy of Economic Sciences as Full Member in 1983, replacing Dr. Carlos S. Brignone, where he gave impetus to its Institute of Economics and attracted a new generation of argentine economists. He was elected as First Vice-president of the Academy in 1998. He received tempting new proposals during the last year.

The academic life of Rolf was at the highest international level. He was invited researcher at the Universities of Harvard, Chicago, and Northwestern and in the Faculty of Mathematical sciences at the Weizman Institute of Sciences. He presented papers in several advanced workshops in his fields of work, with the participation of leaders in all those fields, such as Debreu, Sonnenschein, MacFadden and Mas-Colell, at the Universities of California in Berkeley and of Massachusetts. He was guest speaker in the Third World Congress of the Econometric Society and in several Latin American Regional Meetings of the same Society. He actively participated in practically every annual meeting of the Argentine Association of Political Economy since 1964. His work was published in the leading international journals on economic theory, as the Journal of Economic Theory, Journal of Mathematical Economy, International Economic Review, Econometrica, The Review of Economic Studies. He contributed several articles to the argentine meetings organized by the Central Bank, the National University of La Plata, the National University of Tucumán and to those sponsored by the Central Bank of Uruguay.

Rolf made several important contributions to the economic science, all of them aiming at relevance and applicability. Many of them he pursued throughout his life. In the general equilibrium area he found a constructive proof on the existence of equilibrium, in the sense that calculation is feasible. On economic growth he was ahead of time when he showed the important role of initial conditions under a variable rate of intertemporal preference in models of optimal growth, making possible to predict the kind of economic convergence to be expected between poor, intermediate and rich countries. He demonstrated a theorem of equilibrium under increasing returns to scale, anticipating models of endogenous growth of the eighties. He also gave criteria of optimal economic development useful for welfare analysis. He derived conditions to define an aggregate excess demand function, useful for comparative statics purposes, named thereafter the Sonnenschein-Mantel-Debreu Theorem. He developed general forms of production functions taking as a starting point the elasticity of substitution.

Any influenced him to dedicate some of his time to international economics. Hence they showed that economic integration does not necessarily lead to a zero tariff, and analyzed the effects of integration on the income distribution. In other paper they worked out the social measurement of benefits under integration. They analyzed the advantages of exchange policies of the "crawling peg" type and its optimal alternatives. He alone, by inertia, developed the case of an optimum tariff for small economies and the implications of war of tariffs. In the field of public finance he also evolved the conditions for a general equilibrium under taxes and the conditions for optimal taxes.

Living in Argentina he could not help but thinking about stability, and he analyzed optimal policies for stabilization and the effects of the interest rate policies on the firm under inflation. He also analyzed the interactions between the informal economy and the external indebtedness. While he was assisting the Ministry of Economics he developed formal models for economic planning and optimal planning with unknown preferences. Economic behavior under uncertainty and game theory were also subjects of his interest from the very beginning of his academic life. He was attracted to computational questions and developed software for problem solving. He only failed to generate his own computer as Guy Orcutt did. He also showed his econometric expertise introducing methods for estimating systems of demand equations.

Rolf received many awards in the course of his academic life. In 1976 he was named Fellow of the Econometric Society for his important theoretical discoveries in the field of general equilibrium and economic growth, being the first Latin American to receive such honor. Since then he maintained a long, very close relationship with this international society, being the link between the Society and Latin America. Then, by resolution of the President L. McKenzie, he created, together with Marc Nerlove, Arnold Harberger and John Chipman the Latin American chapter. Rolf presided the first Committee and organized the first Latin American congress in 1980 in Buenos Aires. The next meeting Nr. 17 will take place in Mexico, being this the main Latin American meeting on economics. For many years he was member of the Council of the Society and associated editor of the prestigious journal Econometrica. He was awarded the Bunge y Born prize in Economics in 1993, the most important prize in this field in Argentina. He received a Guggenheim award and the Konex prize in 1996. He was a Senior Researcher of the Conicet, in its maximum category. He was President of the Argentine Association of Political Economy. The National University of Tucumán awarded him with the mention of Doctor in Honoris Causa for his contributions to economic theory and continuous support of the academic development of his Faculty of Economic Sciences.

Rolf was more a Mathematical Economist than a Mathematician inclined to Economics. I always remember him saying that the key for discovering a theorem with economic sense was to investigate at least another two hundred. He always had a mathematical bias when searching to economize on sufficient conditions for demonstrating theorems. As Irving Fisher and John Maynard Keynes he also engaged in financial investments to prove the soundness of his economic guesses. He made even profits investing with some colleagues in the seventies. But Rolf loved uncertainty only in theoretical models, retired early from the market, and could not obtain higher than normal profit rates.

As a couple Rolf and Any remind us of the very few couples where both, husband and wife, are notable scientists. They attained the adequate relationship as such, as parents and friends and colleagues in scientific activity. They contributed many co-authored papers keeping themselves to their preferred fields.

With Rolf's passing our country and Latin America lose an international reference difficult to be replaced. His academic stature is more clearly appreciated after knowing who were his teachers, his mates at the university, his colleagues and his graduate students. In all these groups first-class economists emerge. We are all very much obliged to him for all the work he accomplished in developing an Economic Science in Latin America with international standards. He laid out truths that will remain with us forever. His home, with Any and his son, was an amicable place for all the colleagues. As was rightly asserted at his funeral by the President of the National Academy of Economic Sciences, Doctor Julio C. Cueto Rúa, Rolf was the friend of friends and irradiated a warm feeling of peace, a strange feeling amid arduous academic disputes.

When Harry Johnson died, Paul Samuelson said that he was envious of someone leaving so many works already finished and so many projects in process with such a creative impulse. The same is applicable to Rolf Mantel. And for a long time, the feeling that he is still among us will prevail.

February 19, 1999