them successively. in the bundesbank, annually a large number of vulnerability checks and penetration tests take place. we detect and fix regularly weaknesses of the manufacturers or ourselves in systems and applications. the weak link : people well - known hacker kevin mitnick – who allegedly hacked into the us department of defence ’ s network more than one hundred times and penetrated nsa systems on multiple occasions – once said : “ companies spend millions of dollars on firewalls, encryption, and secure access devices and it ’ s money wasted because none of these measures address the weakest link in the security chain : the people who use, administer, operate and account for computer systems that contain protected information. ” i agree with kevin mitnick. this stems from the fact that, in all of the cyberattacks known to us, attackers focused their attention on people as the weak link : in other words, end users and their behaviour. that is why i think it is essential to raise awareness among users about how to handle data and it systems in a security - conscious manner – and this awareness needs to be conveyed to all those who work with such systems. each and every one of us must develop an understanding of the threats, yet internalise the fact that these threats are constantly changing and that it is possible to protect ourselves. and this applies in both the work and the private setting. in the bundesbank, we regularly discuss current threats, organize seminars focusing on cyber - security, or – like in the past year – perform a large - scale awareness campaign which dealt with subjects like “ data classification ", “ encryption ", “ password protection ", “ mobility ” and “ social engineering ". this means that the analysis and synthesis of vulnerabilities are our tools of choice when it comes to heightening security awareness within the company and to giving management a deeper insight into the actual risk situation. it would be desirable to establish a system of measures and metrics that renders visible the progress already made. 4. is 99 % security enough? while banks can absorb the losses incurred by the default of an average borrower, just one successful cyberattack can bring the activities of a financial market infrastructure to a standstill, causing at least immense reputational damage or in the worst case a financial crisis. the onus is therefore on banking supervisors to keep an even closer watch than they do now on the potential threats posed by cybercrime. and the central banks have a special responsibility to protect themselves from cyber

very low, namely less than 20 % by 1920. moreover, getting a mortgage loan was nearly impossible for most households since a substantial down payment was required. figure 2 : homeownership rates the netherlands. taken from van de zeeuw & kraan ( 2001 ) and eurostat. after world war ii in many countries – including the netherlands – the idea slowly emerged that more homeownership would contribute to welfare, and should therefore be further promoted. in general, the housing shortage at that time meant that governments were willing to take drastic action to stimulate access to housing. the introduction of a mortgage guarantee scheme in 1956 meant that more and more households could access the mortgage market. since the government guaranteed that the loan would be paid off, lenders were willing to take on additional risk, and were able to loosen their downpayment constraints. additionally, households that wanted to buy a newly constructed home were eligible for additional subsidies that were introduced to stimulate building - in dutch called “ premiewoningen ”. meanwhile homeownership and mortgage debt were steadily on the rise. by the 1970 ’ s 35 % of all households were owner - occupiers. and by the early 90 ’ s this number stood at 45 %. currently the homeownership rate in the netherlands is almost 70 %. from the 1990 ’ s onwards the netherlands experienced a spectacular surge in mortgage debt and house prices. from 1995 to 2008 house prices more than doubled in real terms. mortgage debt increased in the same period. from around 50 % of gdp to over 100 % of gdp, as you can see in figure 3. fout! onbekende naam voor documenteigenschap. figure 3 : mortgage debt as a percentage of gdp in the netherlands ( 1950 - 2018 ) it is in this period that households and mortgage suppliers discovered “ innovative ” ways to fully exploit the tax advantages of mortgage interest deduction. new mortgage products were introduced that combined interest - only mortgages - and hence, maximum deduction - with saving or investment accounts that allow for deferred amortization. at that time mortgage suppliers also gradually started to loosen their credit standards. first, by allowing households to increase borrowing by including partner income for determining the maximum mortgage. secondly, by an ongoing increase in the loan - tovalue of new mortgages. borrowing at 110 % ltv was not an exception anymore by the early 2000 ’ s. additionally, households started to withdraw home equity