PE ratios: A new pathway to asset allocation
PORTFOLIO POINT: Using the PE ratios of different asset classes, we can build expectations of future investment returns from the earnings of different assets. The recent 75 basis point interest rate cuts makes cash a less attractive as an investment – something that looking at the PE ratios of asset classes shows.
One of the simpler, and often quoted valuation tools, is the humble Price Earnings ratio. Calculated by dividing the price of a share by the earnings per share, it gives an investor an indication of how much they are paying for every dollar of earnings their investment will provide.
Consider two investments that cost $20 per share each. The first one has earnings of $2 per share, the second one has earnings of $1 per share. The price earnings ratio of the first company will be $20/2 = 10. The price earnings ratio of the second will be $20/1 = 20.
A reasonable question to ask would be why any investor would buy the company with $1 of earnings? The answer is growth. An investor might be prepared to pay $20 for only $1 of earnings if they expect those earnings to grow considerably faster than the company costing $20 per share with $2 per share of earnings.
This simple analysis leads to one of the roles of the PE ratio – as one of the financial measurements dividing the market into 'growth’ and 'value’ stocks. Growth shares are those with higher PE ratios (implying that investors have higher expectations of future growth), and value shares have lower PE ratios.
There is evidence that 'value’ shares provide higher returns than 'growth’ shares. In Australia the Dimensional Australian Value Trust looks to capture this higher return for investing in value companies without trying to pick and choose individuation shares – rather investing in the section of the market with value characteristics. Over the past 10 years it has provided a return of 8.94% pa (after fees), compared with the simple index return over this period of 7.21% pa (to the end of April, 2012).
I think that there is another potential use of the PE ratio – and that is to compare investments between asset classes.
The PE ratio of cash
The media attention in the case of an interest rate cut is usually that of 'good news from the RBA for home owners’. Sure it is good news for those people with variable interest rate mortgages; their repayments are likely to fall. However, for the rest of the world (who happen to be the majority of people) who have either paid off their home loan or are renting, it might even be bad news as the interest paid on their cash investments fall.
A good cash investment – after this interest rate cut – will pay around 5% interest per annum. That will amount to about $5 of interest over a year for $100 invested, or a PE ratio of 100/5 = 20.
Not too many investors would be too excited about a share investment with a PE ratio of 20 – however, in the case of cash, the fact that you capital is virtually secure (provided a well recognised and regulated bank is used) means you can be certain of getting the interest paid and your deposit returned.
The PE ratio of residential property
The earnings of a property are the income that it produces, less the costs to produce that income.
The average price of a capital city property is $448,000 (ABS – March 2012 – Capital City Price Index). In the ABS 'Housing Occupancy and Costs 2009-2010’ data series, the average rent paid to a private landlord in a capital city was $336 per week. This is now almost two years old – assuming rental growth of 10% of the subsequent two years the rental income is now $370 a week, or $19,240 a year. There are many costs that should be taken out of these earnings (agent fees, repairs and maintainance), however, let’s just assume $2,000 a year for rates leaving $17,240 a year on the average capital city property value of $448,000.
This gives a PE ratio of 448,000/17240 = 26.
The PE ratio for Australian shares
It can be frustrating that there is not a consistent measure of the PE ratio of the Australian share market at any one time. However, the data I use suggests a PE ratio of 13.2 for the Australian market at the moment. This is around half the PE ratio of a property investment at the moment – and it would be reasonable to expect earnings from both Australian shares and residential property to grow at around the rate of inflation.
Gold
As one of the 'wonder asset classes’ of recent years, it is interesting to ponder the PE ratio of gold. Gold does not produce any earnings. So, its price (regardless of what is paid) divided by its earnings always gives a PE ratio of infinity – which is certainly at the higher end of things. This emphasises the 'non-productive’ nature of gold as investment, which is why Warren Buffett describes it as having 'no utility’.
Earnings over a Decade
It is interesting to compare what the different asset classes might provide in earnings over the next 10 years. I have invested a hypothetical $400,000 in each asset class, and calculated the earnings over 10 years using the following assumptions:
- Cash – making the best assumption we can that interest rates will average where they are now for the 20 years.
- Gold – no earnings.
- Residential property – earnings (after council rates) to increase in line with inflation each year.
- Australian shares – earnings to increase in line with inflation each year (i.e. both sales and costs increase with inflation).

Under those assumptions, Australian shares looks set to deliver investors the biggest pile of earnings over the next decade – although there are many economic variables that can impact this.
Conclusion
Cash should have an important place in just about every person’s financial situation – providing liquidity (ready and reliable access to cash). The recent interest rate cuts, however, have made it comparatively less attractive. A focus on the PE ratio of investments might help us be a little bolder when investment prices fall and earnings are comparatively stronger – letting us follow the Warren Buffet advice to be 'greedy when others are fearful’.
Frequently Asked Questions about this Article…
The PE ratio (price-to-earnings) is calculated by dividing an investment's price by its earnings per share and shows how much you pay for each dollar of earnings. For example from the article, a $20 share with $2 of earnings has a PE of 10, while a $20 share with $1 of earnings has a PE of 20. Investors use PE to compare value versus growth stocks (higher PE often implies growth expectations). The article notes value-focused strategies — such as the Dimensional Australian Value Trust — have historically delivered higher returns than the broader index over a 10-year period.
PE ratios let you compare how much you pay for earnings across assets (shares, property, cash, gold). The article shows that comparing these PEs can set expectations for future returns from earnings: for example, Australian shares had a PE around 13.2, residential property about 26, and cash (at c.5% interest) a PE of 20. Using PE as part of asset allocation can help you decide where earnings are relatively attractive and when prices may offer buying opportunities.
Following the article's example of a 75 basis point rate cut, a good cash investment paying about 5% interest has a PE of 100/5 = 20. That means you are effectively paying 20 times the annual earnings from cash. While cash yields are lower and therefore less attractive for returns, cash still offers capital security and liquidity when held with a well‑regulated bank.
Using ABS data, the article estimated an average capital city property price of $448,000 and assumed weekly rent of $370 (about $19,240/year), less $2,000 in costs gives $17,240 annual earnings. The PE is 448,000 / 17,240 ≈ 26. That higher PE versus shares reflects the lower rental yield relative to property price under the article's assumptions.
The article cites a PE ratio of about 13.2 for the Australian share market (based on the data the author used). A lower PE versus property (13.2 vs ~26) suggests shares were cheaper relative to their earnings at that time, implying potentially stronger earnings-based returns if earnings grow as assumed.
Gold produces no earnings, so price divided by earnings yields an infinite PE. The article uses this to illustrate gold's non‑productive nature: unlike shares or property that generate income, gold does not produce earnings, which is why some investors view it as having 'no utility' for income-driven returns.
PE ratios help form expectations but are not perfect predictors. In the article's hypothetical example (investing $400,000 in each asset class and assuming cash rates stay where they are, and property and share earnings rise with inflation), Australian shares delivered the largest total earnings over 10 years. The author cautions that many economic variables can change outcomes, so PE should be one input among several in planning.
No. The article stresses cash remains important for liquidity and reliable access to funds, even though recent rate cuts have made cash less attractive for long‑term returns. PE comparisons can encourage investors to be bolder when earnings look strong, but cash still plays a vital role in a balanced financial plan.

