Soft housing and low rates are an excellent combination for home buyers but whereas home values rise with a gradual pace, mortgage rates change in an instant. It's something worth watching.

Each 0.25% increase to conventional or FHA rates adds approximately $16 per month for each $100,000 borrowed. Mortgage rate volatility can change your household budget.

If you're trying to gauge whether rates will be rising or falling, one keyword for which to listen is "inflation". Mortgage rates are highly responsive to inflation.

By definition, inflation is when a currency loses its value; when what used to cost $2.00 now costs $2.15. As consumers, we perceive inflation as goods becoming more expensive. However, it's not that goods are more expensive, per se. It's that the dollars used to buy them are worth less.

This is a big deal to mortgage rates because mortgage bonds are denominated, bought, and sold in U.S. dollars. As the dollar loses value to inflation, therefore, so does the value of every mortgage bond in existence. When bonds lose their value, investors don't want them and bond prices fall. Mortgage rates move opposite of bond prices.

Prices down, rates up.

In today's market, the relationship between inflation and mortgage rates is helping home buyers. The Cost of Living made its smallest annual gain in 6 years last month and the Fed has repeatedly said that inflation will stay low for some time. The combination is driving investors to buy mortgage bonds which, in turn, is suppresses rates.

So long as it lasts, the cost of homeownership will remain relatively low. Combined with the expiring tax credit, the timing to buy a home may be as good as it gets.

According to the Commerce Department's report, February marked the 8th straight month in which Housing Starts straddled the half-million marker, dating back to June 2009.

This is a different slant on the Housing Starts story as told by the press.

Most publications are reporting that Housing Starts fell 5.9 percent in February. Technically, this is true. Housing Starts did fall 5.9 percent last month. However, the Housing Starts data is comprised of three parts:

1. Single-Family Housing Starts
2. 2-4 Unit Housing Starts
3. "Apartment Building" Housing Starts (i.e. 5 or more units)

The press tends to lump all 3 together but that's not relevant for everyday homeowners and buyers.

2-4 unit homes, and apartments and condos are a different housing class as compared to single-family homes and are notoriously volatile, too. Single-family starts are more steady and better reflect the country's housing stock.

Single-family housing starts are up 32 percent over the last 12 months.

Meanwhile, the pace of new buyers has not kept up with the pace of new housing stock. Therefore, because home prices are based on supply-and-demand, the price for a newly-built home was down, on average, 7 percent nationwide in January.

With the federal home buyer tax credit expiring soon, home buyers will likely create new demand for homes. And with Housing Starts holding steady near 500,000, that should push prices higher through the spring months.

In its press release, the FOMC noted that the U.S. economy "has continued to strengthen" and that the jobs markets "is stabilizing". It also said that business spending has "has risen significantly".

This is a slight departure from the Fed's January statement in which housing was not mentioned and business spending was said to be "picking up".

It's also the sixth straight statement from the FOMC in which the Fed described the economy with optimism. This is a signal to markets that 2008-2009 recession is over and that economic growth is returning.

The economy is not without threats, however, and the Fed identified several:

1. High unemployment threatens consumer spending
2. Housing starts are at a "depressed level"
3. Consumer credit remains tight

The message’s overall tone, however, remained positive and inflation is within tolerance limits

Also in its statement, the Fed confirmed its plan to hold the Fed Funds Rate near zero percent “for an extended period” and to end its $1.25 trillion commitment to the mortgage market by March 31, 2010. Fed insiders estimate that the bond-buying program lowered mortgage rates by 1 percent since its start.

Mortgage market reaction to the Fed press release is, in general, ambivalent. Mortgage rates are unchanged this afternoon.

The FOMC’s next scheduled meeting is a 2-day affair, April 27-28, 2010.

The FOMC has held the Fed Funds Rate in a target range of 0.000-0.250 percent since December 16, 2008, and the voting members of the Fed are expected to vote "no change" again today.

However, no change in the Fed Funds Rate doesn't necessarily mean no change in mortgage rates. This is because the Fed Funds Rate is a different interest rate from the rates home buyers get from a loan officer.

• Fed Funds Rate : Short-term rate at which banks borrow from each other
• Mortgage Rate : Long-term rate of interest a homeowner pays on a mortgage

Mortgage rates are more responsive to what the Fed says as compared to what the Fed does.

After each FOMC meeting, Fed Chairman Ben Bernanke & Co issue a formal press release to the markets. At roughly 400 words, the statement is a brief commentary on the strengths, weaknesses, and threats for the U.S. economy.

Wall Street watches the statement with great interest and this is why mortgage rates are often volatile on the days of an FOMC adjournment. One mention of a word like "inflation" and traders rush to dump their mortgage bond positions.

Inflation is the enemy of mortgage rates.

After the Fed’s last meeting in January, it told us that the economy had "weakened further", led by steep declines both in housing and employment. Global demand was off, too. The negative tone of the Fed's statement caused mortgage rates to fall to near an all-time low.

This month, expect a less gloomy message.

Since January, there's been a modest rebound in housing, employment appears more stable, and Retail Sales just posted huge gains. If the Fed alludes to improvement in any or all three, mortgage rates will likely reverse and zoom higher.

We can’t know what the Fed today will say so if you're floating a mortgage rate and wondering whether to lock, the safe approach would be to do it today, prior to 2:15 PM ET.

FHA and conventional mortgage rates rose last week, marking the first time that's happened this month.

Mortgage rates have been on impressive run lately and mortgages are priced far better than what most experts predicted. Weaker-than-expected economic data is one reason why. Lack of economic data may be another.

This week, however, data returns.

• Monday : Industrial Production and Home Builder Index
• Tuesday : Housing Starts and Building Permits
• Wednesday: Consumer Confidence
• Thursday : Producer Price Index and Initial Jobless Claims
• Friday : Consumer Price Index and Continuing Jobless Claims

And, as if all that weren't enough to spook you, the Federal Open Market Committee meets for a scheduled, 1-day event Tuesday.

The Federal Reserve is expected to vote to hold the Fed Funds Rate in its current target range near 0.000%, but that doesn't mean mortgage rates won't change. Markets are responsive to the FOMC's post-meeting press release and any clear talk of economic strengthening should drive rates higher.

Wall Street is in Wait-and-See Mode and this week will give it plenty to look at.

If you're floating a mortgage rate, or waiting to lock, be prepared for wild swings in mortgage rates -- especially leading up to Tuesday afternoon's FOMC adjournment. The Fed adjourns at 2:15 PM.