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.

Paul Schmidt's invention has been shining for almost 120 years. With his batteries for flashlights and bicycle lights, the Berlin entrepreneur made energy mobile and light transportable. From a tinkerer who was once at the top and at the bottom again. Paul Schmidt had the brilliant idea on a cosy Sunday morning, at home in the kitchen of all places. His wife Henriette Auguste Franziska Laura was pouring milk onto flour. Immediately the liquid is absorbed, a solid mass is formed. Paul sees this, storms out of the kitchen and runs to his "Elektrotechnische Anstalt von Paul Schmidt". For some time now, the 28-year-old Berliner-by-choice has been looking for a way to make light transportable. But nothing really works, back in 1896. Could...

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?

Secondary private equity. Because private equity funds have been generating double-digit returns for years, this asset class is finding more and more friends among wealthy investors. But there is still room for improvement. "Used fund shares - Secondary Private Equity - are just as yield-strong and avoid substantial disadvantages of the PE funds , make Florian Dillinger, Matador partner Group AG, clear.

Real estate. Prices on the real estate market have been rising massively for the past five years. As a result, yields - so-called cap rates - have fallen in many areas to levels that hardly cover financing and maintenance costs. Is it worth thinking about real estate investments at all now? Klaus Trescher, Kriton Immobilien, says: "Yes - but you have to find the rare occasions."

Urbanization. More and more people are moving to the cities. In order for these to remain worth living, extensive investments are necessary. "This will benefit those companies that offer solutions," explains Ivo Weinöhrl, fund manager at Pictet Bank.