Guilherme Arinos made a career at Banco do Brasil and during the war started a lifelong friendship and association to President Getúlio Vargas.

Arinos was a member of the first board of directors of the Brazilian National Development Bank, BNDES, and later, at the private sector, was a high ranked executive of Volkswagen do Brasil and one of the founders of Banco Garantia.

At PUC-Rio he had his first job as teaching assistant working with Edmar Bacha, then preparing a macroeconomic textbook, self-defined as of a neo-structuralist approach, and later to become very popular in Brazil, with several editions[1] Winston Fritsch was his advisor in his M. A. thesis on the topic of financial euphoria and crash in the early years of the Brazilian Republic (1889-1890) and the attempts at monetary reform in connection either adhering to the gold standard or, alternatively to experience with fiat currency models, as proposed by Ruy Barbosa.

This work was published as a book titled Monetary reform and instability during the republican transition ("Reforma monetária e instabilidade durante a transição republicana"") and became a reference to the period it covers.

He had brief fellowships at the CFIA (Center for International Affairs), CES (Centre for European Studies) and National Bureau of Economic Research (NBER).

The applied chapters were case studies for Germany, Austria, Hungary, and Poland, also including some common themes like the relation between external imbalances, dollarization and fiscal reforms in the context of specific stabilization experiences.

He had an intense academic activity during these years; his research interests had three key themes: (i) on high inflation and on the basis of topics and issues raised in his doctoral dissertation; (ii) on Brazil's economic history, mostly in connection with macroeconomic and monetary issues; and (iii) on trade policies, multinational enterprises and economic development, in collaboration with Winston Fritsch.

399, March 1990) disputed Thomas Sargent's popular explanation to the sudden end of hyperinflation as result of a wide-ranging fiscal "regime change".

[4] Much later, in 1995, Thomas Sargent wrote an article on the Brazilian URV, evoking the German experience with the rentenmark and arguing, as per the mathematician David Hilbert, that one could not solve the hyperinflation problem by "changing the name of the independent variable".

Later, his research on the early years of the Republic would communicate well with his work of Machado de Assis newspapers articles as per his selection of chronicles under the title "O olhar obliquo do acionista" ( "Shareholders oblique look", as literal translation).

In sequence, Franco and Fritsch worked in two projects directed by Gerry Helleiner for WIDER (World Institute for Development Economics Research) of the United Nations University during 1990 and 1991.

The second, on the same issues but focused on trade and industrial policies was published as "Import repression, productivity slowdown, and manufactured export dynamism: Brazil,1975-1990" in Gerry Helleiner (org.)

[10] Franco would return to these themes only after 1995 when, as deputy governor of the Central Bank responsible for international affairs organized a Census on foreign direct investment into Brazil that has been conducted and published each five years since 1995.

On August 20, 1997 he was confirmed governor[11] of the Central Bank of Brazil, until leaving on January 9, 1999, and briefly returning in March 1999 to transfer his functions to his successor Arminio Fraga.

In his memoir, Cardoso recollects that “with a small team facing a gigantic challenge, as a Brancaleone's Army, ... we started to work, under a very discouraging political atmosphere”.

The team's first major announcement was described by Franco, as a “non-package” or rather “an ambitious collection of medium term fundamentalists agendas”,[13] curiously named as PAI (acronym for Plano de Ação Imediata, Plan of Immediate Action), released on June 13, 1993.

Simultaneously, Pérsio Arida was designated president of BNDES, and André Lara Rezende replaced Malan was chief negotiator of then pending Brazilian external debt.

In parallel, Franco had executive responsibilities in International Affairs at the Central Bank related to operational aspects of external debt restructuring under the Brady Plan, then at decisive moments, the administrative structures in charge of exchange controls, bound to be transformed by an ambitious deregulation process, the FOREX trading desk and international reserves management.

However, IMF representatives did not feel comfortable with the drafts of the Real Plan shown during the negotiations of the stand-by agreement and refused to go on with the loan, forcing the Brazilian authorities to develop some alternative strategy to acquire the US Treasury bonds in the secondary market using Brazil's international reserves.

[18] The Real Plan had as central element a monetary reform effected through three successive measures: the first and more important introduced on February 28, 1994,[19] created the URV (Unidade Real de Valor) mechanism, that is, a "money of account" to be freely used in contracts and obligations in order to realign relative prices and coordinate price fixing around the exchange rate.

In consequence, the exchange rate between the URV (now the real) and the Dollar, fell below R$1,00 (i. e. it appreciated) with a great positive impact on expectations and marking the successful conclusion of the stabilization process first phase.

[24] These failed experiments were called "heterodox shocks" not only because of direct intervention in prices and intrusive currency reforms, but also for their practical disregard of fiscal "fundamentals" and monetary policies.

the National Monetary Council was recaptured and reduced to three members (ministers of Finance and Planning and the Governor of the Central Bank), recomposing the commitment of top level decision making to price stability.

Sometime later a Monetary Policy Committee (known as COPOM - acronym of Comitê de Política Monetária) was created securing Central Bank's independence in fixing the interest rate.

[26] After a sabbatical year back at the Catholic University as full-time professor, Franco founded an investment company named Rio Bravo Investimentos, based in São Paulo, to manage mutual funds, structured products, and private equity, in association with Swiss Re.

In August 2001 Rio Bravo acquired a broker dealer called Mercurio DTVM and started to manage REITs (Real Estate Investment Trusts) and also with the public distribution of securities.