Valeria Diaz is a seamstress working in a ''tintoreria'' (dry cleaner's shop) in the Tacubaya section of this sprawling city.
She is typical of many working-class people who are just barely making it on their skimpy wages as Mexico's economy slumps into recession.
But Valeria feels she is better off today than she might have been if she had stayed on her father's farm in the hill country near Guanajuato, a four-hour drive from here.
''Dad wanted me to stay with him after Mom died,'' she said over a cup of cinnamon-laced sweet Mexican chocolate in a cafe near the dry cleaning plant. ''But I saw how hard he worked and didn't want to get caught in that treadmill.
''Maybe I'm a little selfish,'' she confessed. ''No, that's not it. I just wanted more out of life than a farm career. I had gone to agricultural school, learned a lot about seeds and fertilizers, and learned even more working with dad and my brothers on the farm.''
But like her brothers before her, she decided that farming was not her lot in life. The three brothers all went to Monterrey in northern Mexico to work in industry. She came here to Mexico City.
''It made dad a little unhappy. And he doesn't have anyone in the family who wants to take over the farm. After my brothers went north, he hoped I would be like his neighbor, Jose Ramon, who got his daughter Cecilia to take over the farm after her brothers came here to work. I couldn't do it.''
She works hard -- an 11-hour day -- and takes home the equivalent of $20 a day. That's fairly good pay for lower-middle-class Mexicans, but with inflation at 30 percent or more and food costs soaring, that wage does not go as far she would like. The late February devaluation of the Mexican peso has hurt even more. Devaluation already has cut the US dollar value of the peso by 40 percent, and it may slip more.
''A lot of us are being pinched. Being here in Mexico City is not as glamorous as I expected,'' she adds. ''But I am glad I came.''
Valeria knows little about Mexico's economy. Her concerns are naturally concentrated on her own lot. Yet behind her decision to move here was a national problem - the plight of agriculture, which has bedeviled Mexican governments for generations and forced this nation to import sizable quantities of food.
Now, as she ekes out a precarious existence here in Mexico City, living in a one-room apartment without hot water, Valeria is seriously affected by the state of the Mexican economy, which at this moment is weaker than it was when she came to Mexico City two years ago.
That was in late 1979, when Mexico's oil boom was taking off and the future looked rosy for Mexico and Mexicans.
Today, the blush is off the bloom in the Mexican economy. Austerity and sacrifice are words being heard here more and more.
''No doubt we are faced with many problems, but with the unity and solidarity of all Mexicans we can overcome them,'' Mexican President Jose Lopez Portillo said in an interview.
But Mr. Lopez Portillo, trying in his last year in office to get Mexicans to sacrifice, has a credibility problem. Many blame his administration for the economic difficulties. His successor, Miguel de la Madrid Hurtado, is blamed even more, for he was the architect of the Lopez Portillo economic plan emphasizing capital investment in plant and new industry over Mexico's social needs.
Those social needs are becoming all the more pressing as the world oil glut forces down the prices of Mexican petroleum, with a consequent loss of $6 billion in earnings expected for 1982. That has slowed Mexico's ambitious development plans, with a postponement of $4 billion in projected development spending. Such spending in the past two years is blamed for the inflation that bankers estimate is even higher than the government figure of 30 percent yearly. Foreign reserves are down from $5 billion at the start of 1982 to about $1 billion today. And with a foreign debt of at least $60 billion, that reserve is not enough cushion.
Moreover, more and more Mexicans entering the job market are not finding work.
Population growth has slowed slightly in recent years, but it will take 15 years or so for this slowing to have an affect on the number of Mexicans coming onto the job market each year. At the moment Mexico needs to create at least 800 ,000 new jobs a year just to take care of the surge of young people. Bankers and business people here say the Mexican economy isn't doing it -- despite government claims.
''What we are seeing is a staggering buildup of unemployed and underemployed people,'' says an economist for the Banco de Comercio, Mexico's largest bank. ''This is our biggest problem.''