Final answer:
The adoption of the euro has had mixed effects on economic efficiency in European companies. It has not necessarily led to an increase in the cost of capital. In terms of the decline in the overall level of savings, the adoption of the euro in itself cannot be directly attributed to this.
Step-by-step explanation:
The adoption of the euro has had mixed effects on economic efficiency in European companies. It has not necessarily led to an increase in the cost of capital. In fact, the euro has made it easier for companies to access capital markets in other European Union countries, leading to increased competition and potentially lowering the cost of capital. However, it is important to note that the impact of the euro on economic efficiency varies across different companies and industries.
Regarding the decline in the overall level of savings, the adoption of the euro in itself cannot be directly attributed to this. The level of savings in a country depends on various factors such as government policies, cultural norms, and individual preferences. The adoption of the euro may have indirectly impacted the level of savings in European countries due to the financial crisis and austerity measures that some countries had to undertake.