A letter from... Sabine Holzknecht. The author of private wealth has been honorary chairwoman of the organization "Help without Frontiers" for four years. She appeals to our solidarity.

A letter from ... Carsten Mumm. The chief economist of the bank Donner & Reuschel thinks about the monetary policy of the next decade.

A letter from ... Hans-Werner Sinn. The emeritus president of the Munich ifo Institute questions climate policy and the overestimated role of electric cars in achieving climate goals.

From an engineering point of view, the turn to the electric car can now be welcomed - it is elegant, robust, has a strong sprint, drives quietly and does not require a complicated gearbox. But: Es cannot be moved without CO2 emissions, as the European legislator claims, if it includes the CO2 emissions of these cars with a value of zero in its calculations.

A letter from ... Caroline Kuhnert is responsible for high net worth individuals at UBS. Sie explains why wealth can have a positive effect far beyond the economy.

We've just published our fifth Billionaires Report. Our aim is to contribute to a better understanding of this exclusive group of people. How has their wealth changed? Aber above all: What is the influence of the high-net-worth individuals on our society? And are there regional differences?

A letter from ... Professor Marcel Fratzscher. The head of the DIW sees the current justice debate as misguided and calls for an inclusive social market economy.

"Time for Justice" was the motto of Martin Schulz's election campaign. In a country where 70 per cent of people feel that inequality is too high, this slogan may catch fire. I still think: Wir need a debate that goes beyond justice.