Opinion – Marcos Lisboa: Mandinga, opportunism and science

The pandemic has revealed that part of society finds it difficult to interpret and use the results of science. The controversy over how to fight Covid was not restricted to politics. Doctors defended the “preventive treatments” advertised by the Planalto. In everyday conversations, some said “I know someone who took the vaccine and died. Therefore, the vaccine doesn’t work”. Parents signed manifestos against schools that required vaccination certificates for children to attend classes.

These controversies should not be surprising. Science is shaky ground where certainty has no place, unlike religion. The Bible and the Qur’an can calm believers by delimiting rules and truths, but science, which saves lives and not souls, is the ground of pondered doubt.

In scientific practice there is no way to guarantee the truth. A drug may have proved effective in many cases, but it eventually has unexpected side effects. Empirical results incompatible with the dominant models are usual in the history of science, motivating new research.

The scientific method seeks to adopt procedures to verify the degree of robustness of conjectures. In the case of health treatments, one step is to draw, among a large group of people, one part to take the drug, the other to take an innocuous substance, without anyone knowing what they are ingesting. It is then possible to observe whether the group that took the drug has fewer problems than the others.

A single survey, however, is not enough. The people selected may have specific characteristics, or the result may be fortuitous. For this reason, experiments are repeated in many different circumstances. The drugs we use in our daily lives must go through this excruciating process of tests that try to give greater reliability to their prescription.

For centuries, doctors administered bloodletting to the sick, believing that they could cure them. As there was no scientific method, it was not tested whether bleeding guaranteed better recovery than other practices. Survivors were grateful for the treatment. The rest were to accept God’s choice.

We are all subject to prejudice. Many easily adopt conspiratorial narratives that seem to account for what we observe, pinching convenient data here and there to justify their argument. On the other hand, the protocols of science and the care with the method of analysis seek to guarantee mechanisms to try to prevent us from fanaticism motivated by our subjective perceptions.

The most recent research on the use of chloroquine in patients with Covid indicates its ineffectiveness. Vaccines have reduced the death toll significantly. It’s the best we have at the moment.

The many controversies during the pandemic revealed opportunistic use of science. Some declared themselves indignant at the Planalto’s proposals, but in other areas of public policy, they defend theses equally poorly supported by evidence.

The analysis in economics has historically suffered from low computational capacity, inadequate databases, and less robust attempts at causal estimation. In recent decades, however, the improvement of research designs has made it possible to identify causal relationships with greater reliability, including the adoption, as far as possible, of random experiments and other techniques, such as quasi-experiments. Angrist, Nobel laureate in economics in 2021, and Pischke systematize this agenda in The Credibility Revolution in Empirical Economics, published in the Journal of Economic Perspectives.

The public policy debate in Brazil, however, often overlooks empirical evidence. There are many results, for example, on management techniques in education and their positive impact on student learning. The approval of the new Fundeb ignored this literature and essentially resulted in a linear increase in income for active and retired teachers.

There were those who defended in Brazil, a few years ago, that the high interest rate of the Central Bank (BC) would be responsible for the recurrent rise in prices. Inflation would be reduced if the BC chose to reduce its interest rate.

The thesis may be seductive, but is there empirical evidence? Were there countries that lowered their interest rates and brought inflation under control, while others raised it, having opposite effects in similar circumstances? Recently, Turkey followed the protocol advocated by heterodox people and reaped the opposite of what was intended: the exchange rate devalued and inflation increased.

Sixty years after the creation of Sudene, shouldn’t we analyze what went wrong in regional development policies? To what extent were tax benefits, such as Simples or the chemical industry tax exemption, successful? Many sectoral interventions strengthen groups that survive thanks to official favor. They resist impact assessments and oppose withdrawal of benefits, even when interventions fail.

Public policy should follow, as far as possible, protocols similar to those adopted in health. Are there microdata surveys and control groups carried out in other countries? What are the details of public intervention measures in these countries and their results? How robust are the instruments used to assess the impact of these policies in Brazil and how can we ensure that they will be reviewed in case of frustration with the results?

The procedures of science do not guarantee good results, but they allow us to recognize failures and can suggest new paths. To stop repeating old mistakes would already be an advance.