"We expect market participation rates will grow over the next 20 years due to a number of factors, both economic and technological."
Technology changes are also making it easier to get involved with people now able to participate and vote in listed company annual general meetings online.
Wallis said greater scrutiny was also possible with extra levels of disclosure coming into force this year.
Audit reports which usually come at the end of a company's annual report will now have to include a 'key audit matters' section where the auditor will have to highlight which issues were more significant or concerning when undertaking the audit.
In the past auditors only said something when a company was no longer a "going concern" - often too late for investors.
"In the UK, where the KAM [key audit matters] requirement has been in force since 2013, it has been welcomed by shareholders for the insight it provides into the company's performance and risk profile," the report noted.
Wallis said he expected the extra level of detail to prompt more questions at annual general meetings.
Investors will also get greater insight into chief executive pay and diversity policies through a new NZX corporate governance code coming into force from October.
Companies have had to report the number of women on their boards and in officer roles since 2012.
But the report will require all listed companies to have a diversity policy and report against it. Those who don't will have to explain otherwise.
Wallis said its research showed standards for companies and boards were increasing with directors becoming more professionalised.
"Most boards have recognised they need to bring through new perspectives."
At larger companies there was a greater focus on gender diversity.
But one area that did surprise Wallis was that newer listed companies were less likely to have women on their boards despite the increased focus on the issue in recent years.
It found the proportion of women directors was highest among issuers that have been listed for more than 10 years at 20.75 per cent.
Among those listed within the last five years, it was 18.2 per cent and 17 boards out of the 75 it analysed had no female directors.
Wallis said there was also a greater level of director independence than he had expected which was a result of fewer block ownerships of companies.
Of the 75 companies 76 per cent had a majority of independent directors and 21 per cent had all independent directors.
It found 77 per cent also had an independent chair and that rose to 90 per cent for the top 30 companies.
Highest paid chair
Fletcher Building chairman Sir Ralph Norris earns by far the biggest base salary of all the chairs of the top listed companies.
The Chapman Tripp report shows Sir Ralph's base salary is over $400,000.
The majority of chair positions in the top 30 listed companies had a base salary of less than $200,000.
Fletcher Building is one of the biggest listed companies in New Zealand with a market capitalisation of over $5.2 billion.
Spark chairman Mark Verbiest had the second highest base salary.
Auckland Airport, Fisher &Paykel Healthcare, Contact, Ebos, Sky City, Air New Zealand, Trade Me and Chorus chairs also had base salaries over $200k.
The report found there was a wide variance in director and chair base fees with some companies also paying separate fees on top for additional responsibilities.
But the report also noted a recent survey by remuneration consultants Strategic Pay which found New Zealand directors are paid 38.5 per cent less than their Australian counterparts and chairs about 36 per cent less.
