Is Mercury NZ Limited's (NZSE:MCY) 9.6% ROE Better Than Average?

Many investors are still learning about the various metrics that can be useful when analysing a stock. This article is for those who would like to learn about Return On Equity (ROE). To keep the lesson grounded in practicality, we'll use ROE to better understand Mercury NZ Limited (NZSE:MCY).

Our data shows Mercury NZ has a return on equity of 9.6% for the last year. One way to conceptualize this, is that for each NZ$1 of shareholders' equity it has, the company made NZ$0.10 in profit.

View our latest analysis for Mercury NZ

How Do You Calculate Return On Equity?

The formula for ROE is:

Return on Equity = Net Profit (from continuing operations) ÷ Shareholders' Equity

Or for Mercury NZ:

9.6% = NZ$336m ÷ NZ$3.5b (Based on the trailing twelve months to December 2019.)

It's easy to understand the 'net profit' part of that equation, but 'shareholders' equity' requires further explanation. It is all earnings retained by the company, plus any capital paid in by shareholders. The easiest way to calculate shareholders' equity is to subtract the company's total liabilities from the total assets.

What Does Return On Equity Signify?

ROE measures a company's profitability against the profit it retains, and any outside investments. The 'return' is the amount earned after tax over the last twelve months. A higher profit will lead to a higher ROE. So, all else equal, investors should like a high ROE. Clearly, then, one can use ROE to compare different companies.

Does Mercury NZ Have A Good Return On Equity?

One simple way to determine if a company has a good return on equity is to compare it to the average for its industry. The limitation of this approach is that some companies are quite different from others, even within the same industry classification. As is clear from the image below, Mercury NZ has a better ROE than the average (6.7%) in the Electric Utilities industry.

That's what I like to see. I usually take a closer look when a company has a better ROE than industry peers. One data point to check is if insiders have bought shares recently.

Why You Should Consider Debt When Looking At ROE

Companies usually need to invest money to grow their profits. That cash can come from issuing shares, retained earnings, or debt. In the first and second cases, the ROE will reflect this use of cash for investment in the business. In the latter case, the use of debt will improve the returns, but will not change the equity. That will make the ROE look better than if no debt was used.

Combining Mercury NZ's Debt And Its 9.6% Return On Equity

Although Mercury NZ does use debt, its debt to equity ratio of 0.34 is still low. The fact that it achieved a fairly good ROE with only modest debt suggests the business might be worth putting on your watchlist. Careful use of debt to boost returns is often very good for shareholders. However, it could reduce the company's ability to take advantage of future opportunities.

But It's Just One Metric

Return on equity is one way we can compare the business quality of different companies. In my book the highest quality companies have high return on equity, despite low debt. If two companies have around the same level of debt to equity, and one has a higher ROE, I'd generally prefer the one with higher ROE.

But when a business is high quality, the market often bids it up to a price that reflects this. Profit growth rates, versus the expectations reflected in the price of the stock, are a particularly important to consider. So you might want to check this FREE visualization of analyst forecasts for the company.

But note: Mercury NZ may not be the best stock to buy. So take a peek at this free list of interesting companies with high ROE and low debt.

If you spot an error that warrants correction, please contact the editor at editorial-team@simplywallst.com. This article by Simply Wall St is general in nature. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. Simply Wall St has no position in the stocks mentioned.

We aim to bring you long-term focused research analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Thank you for reading.