Core and equilibrium in incomplete markets

Conclusions The classical foundation of general equilibrium analysis by the cooperative concept of the core has been extended to an economy with incomplete trading possibilities. This has been accomplished by restricting the exchange possibilities of coalitions of traders in accordance with the available market structure. However, compared with the classical result, the present foundation of rational expectations equilibria may appear much weaker. The reason is that in reality consumers may sign contracts which are more complex than the existing market structure. Therefore, it may happen that prices cannot decentralize all cooperative transactions by markets, in spite of perfect competition. With an incomplete set of markets, therefore, a cooperative exchange of commodities by individual contracts may coexist with trading in non-cooperative, competitive markets.I wish to thank Martin Hellwig for helpful comments and suggestions. Of course, I remain responsible for all shortcomings of the paper.     

Choosing and using payment instruments: evidence from German microdata

Germans are still very fond of using cash. Of all direct payments transactions in 2008, cash accounted for an astounding 82 % in terms of number and for 58 % in terms of value. With a dataset that combines transaction information with survey data on payment behaviour of German consumers, we shed light on how individuals decide on their cash usage. We employ a two-stage empirical framework which jointly explains payment card ownership and the use of cash. Our results indicate that cash usage is compatible with systematic economic decision making. Consumers decide on the adoption of payment cards and then use available payment media according to transaction characteristics, the relative costs of cash and card usage, socio-demographic characteristics and their assessment of payment instruments’ characteristics. Importantly, older consumers use significantly more cash than younger consumers. We show that this difference in payment behaviour is not attributable to age as such but largely to differences in the characteristics of older and younger consumers. This suggests that the high cash intensity of older consumers cannot fully be attributed to the role of habit or to their slow adoption to new payment technologies.     

Intertemporale Zielkonflikte in der makroökonomischen Politik

Der Nobelpreis für Wirtschaftswissenschaften 2006 wurde an Edmund S. Phelps für seine „Analyse von intertemporalen Zielkonflikten in der makro?konomischen Politik“ vergeben. Wie beeinflussten seine Beitr?ge die konkreten Politikentscheidungen und das Design politischer Institutionen? Welche Bedeutung hatte und hat Phelps für die moderne Makro?konomik?     

Exploring the market risk profiles of US and European stock insurers

Market risks account for an integral part of insurers' risk profiles. We explore market risk sensitivities of insurers in the United States and Europe. Based on panel regression models and daily market data from 2012 to 2018, we find that sensitivities are particularly driven by insurers' product portfolio. The influence of interest rate movements on stock returns is 60% larger for US than for European life insurers. For the former, interest rate risk is a dominant market risk with an effect that is five times larger than through corporate credit risk. For European life insurers, the sensitivity to interest rate changes is only 44% larger than toward credit default swap of government bonds, underlining the relevance of sovereign credit risk.     

Structural transmissions among investor attention,stock market volatility and trading volumes

We employ data-based approaches to identify the transmissions of structural shocks among investor attention measured by Google search queries, realised volatilities and trading volumes in the United States, the United Kingdom and the German stock market. The two identification approaches adopted for the structural vector autoregressive analysis are based on independent component analysis and the informational content of disproportional variance changes. Our results show robust evidence that investors' attention affects both volatilities and trading volumes contemporaneously, whereas the latter two variables lack immediate impacts on investors' attention. Some movements in investors' attention can be traced back to market sentiment.